All a bit...Overwhelming. Where do I start?

I'd recommend starting with something like Game Maker. It is well liked among its user base and is capable of some impressive things.

Sadly, I don't know much in the way of Java, but from what I've seen it's fairly easy to get started with.

Here's the thing though, that big game concept you have written? Set that aside for a little bit, or it may well never see completion. If you want to go the programming route, I suggest looking up some tutorials and getting more familiar with the language and programming concepts before jumping into your project. If you want to go the Game Maker route make some simple games and get familiar with the toolset first.

You don't want to try and learn to program (or use a new tool) while you're working on your dream project as it will just end in frustration. A great article on this

by Tommy Refenes (of Team Meat) can be found here. He's answering a set of FAQ's he gets in his email since the successful launch of Super Meat Boy. It's a great read and might help get you in the right mindset.

1. Get better at programming

2. Start with an easier, smaller project that involves 0 story.

3. Finish that smaller project

4. Now you can start to think about something bigger

What is your goal? Are you simply looking to make a game or are you looking to know how to program? A graphical game will be well above the capabilities of a beginner programmer; there's just too much involved. If all you want to do is make a game use a tool like Game Maker. If you really want to do it with a programming language you are going to have the spend time getting better at general programming before doing something as ambitious as this.

... and I'm going to make my own game ...

love the spirit. But I agree. It is really an uphill battle and you should have started with some research ... not by posting this.

There are many tutorials and articles like:

http://zetcode.com/tutorials/javagamestutorial

... but none that will guarantee that you will reach your goal. You need to become a programmer or team up with (at least) one.

What do you mean exactly by 'written out in screenplay format'?

Do you mean you already did the pseudocoding? Like: "if you press the left key, the character will walk at a speed x towards the left, if it bounces against an opponent, it'll stop, a sound is played, the character will react by doing this and that etc.etc. "

I'm affraid that programming involves a little more than this. But really just look at a basic Java program (I'm going to assume you'll use Java as you already have some experience) you'll see that even creating a simple guessing number name takes time to write. "Input number and compare target number with input" actually translates into quite a bit of code where you have to process the keyboard input and in the end present it to the screen using the correct coördinates, font, size etc. in case of a graphical application. Even creating a simple empty window requires quite some effort.

If you don't want to learn how to program, you'll end up using a game maker program. This should be self explainary if you just read the manual and look at some examples.

Other options include hiring people to do it for you, but this will cost money and don't expect to make anything back as the web is crowded with simple free games made by hobby programmers such as myself.

Good luck with your project, but you should probably adjust your expectations as the programming is going to be the hardest part of the production process.

Start right here.

If nothing else, that will teach you where to start.

Wanted to chime in with a little less cynical view here. Deallo sounds to have done something that 90% of indie teams neglect (and leads to failure) and that is it sounds as if he has a design document! A little more to the point I want to point out that you are off to a GREAT START. The design document explaining the story board, characters, required assets and mechanics IS the foundation of any and every game that has ever actually been completed and sold.

From here you will really want to decide if you will be involved with the development process or if you are going to purchase the required labor. I say purchase because I assume you actually want to finish the project and with no monetary incentive most talented individuals won't even give you the time of day let alone actually spend their valuable time creating something for you. In many cases Indie teams work under profit sharing contracts and in many cases they utterly fail to get so much as an intro screen or demo going.

So with that said, and knowing that you have a bit of Java experience under your belt I would assume that you are interested in being a programmer. This is a good aspiration but realize you are years from being able to code it on your own (assuming you dedicate the majority of your free time to practicing and studying). Spend this time gathering the assets that you will need. Simply put it's easier for a programmer to adapt code to various graphics styles, techniques and formats than it is for an artist to "follow your rules". As a programmer you just have to accept that your artist is going to do it their way and you will make it work (unless you pay good money for a highly talented artist, at which point the table turns that they need to EARN their money and give you exactly what you ask for).

Anyway, trying to stay on point here. Your next step is actually 2 parts. Get graphics and STUDY! If you are going to be using your own money to purchase commissioned graphics from artists than start doing that now. Start getting your main character and some level design's / assets in the works. These are normally the longest part of the development process and they need to start well before any actual coding happens (otherwise you will have a nearly finished game waiting on graphics and then requiring modifications because the artists did something a bit different than you expected).

So on to the studying and coding while you are looking for artists (or saving up the money to purchase your assets). You want to completely forget the idea that your trying to build a game and actually learn the fundamentals of programming. What are variables, what are data types, what are pointers, dynamic memory, classes or objects, collections, lists arrays, functions & methods, including external libraries both static and dynamic, threading inputs and outputs and so on. You should be able to spit out the definition of everything I just mentioned off the top of your head along with a little description of what it would do in practice. If you can't do that, your not ready to start your game.

All in all, you actually did (and are doing) the correct first step which is design. Design design design, it is THE most important part of any game. The more you write, the better it turns out, the easier it is to build a team, the easier it is for everyone to do what they are supposed to and so on. The development process will take talented individuals (not beginners) to complete, those talented individuals have spent thousands of hours of their lives perfecting their craft and not to sound rude but it's not worth their time to work without incentive (eg money). Some of us will work under profit sharing contracts and we all think of them differently. Personally my first question is "Let me see your design document". I will read it and determine if I feel it has potential of making money or not, if I feel it has a decent chance in making me some money my very next question is "Show me the graphics you have prepared". If the design document isn't complete or there are little to no graphics ready I won't be interested. Many of my colleges are also professional programmers and this is a common consensus. Either pay me up front or show me that you have almost everything i need to do my work and that you have a good looking game that has a good chance of making me money. If you are going to be doing the coding it's going to be one hell of an uphill battle, start spending at least 2 - 4 hours a day (every day) reading books, tutorials and practicing your coding. If you find it difficult to keep your at it or you regularly lose interest, start thinking of another position. A programmer has to know a lot about the language they are using and how computers work and they have to have a ton of practice. If you don't enjoy it you just wont be good at it.

I could continue but I think I've rambled enough on this thread, my profile here or my gravatar profile have instant messenger contact information that you can reach me directly on. I am a professional programmer that works at this machine 10 - 12 hours a day 6 days a week, I'm almost always available and I can give you some more information at least from the coding and general design / development perspective if your interested. Do keep in mind that I am not the authority on game development and there are many different paths, the things that I suggest and recommend are just what I have seen from indie teams who have failed and teams who have actually sold their game. My statements come from my personal real world experiences and may or may not help others, just depends on the game, the market, the design, the team and the goals. If nothing else at least I can offer some real world advise.

http://en.gravatar.com/daniwan

Step 0: Have vision.
Step 1: Design a game or have a game idea you want to make.
Step 2: Build the game according to your game design
Step 3: Test and revise your game over and over again until it's exactly what you want
Step 4: Market and release the game to the world

Naturally, step 2 is going to be the most difficult step to do because it's going to require a bunch of skills which you may not necessarily have at the moment. That's okay. This is where you teach yourself everything you need to know, or find people who have the skills you need and you can convince them to work on the project. You'll be learning the exact skills you need and you'll be building your project at the same time, so you get two birds with one stone. You'll go through some learning pains, you'll experience frustration, moments of glee and excitement, your project may succeed or fail, but if you stick with it, you'll learn a ton along the way, gain valuable experience, and possibly a marketable product to sell.

Bottom line: just do it.
What matters is what you create.

As for languages & platforms, I recommend Unity3D with C#, or C# with XNA.

As for producing your game, you're going to need programming, art, music and sound, and possibly writing. Sounds like you have the writing covered.

The best advice I can give you is to keep your game simple enough for a single person and beginner to complete. A polished and completed yet simple game is infinitely more valuable than a complex but incomplete, unpolished game. Keep your features/requirements few! Think along the lines of old atari games, like "Pacman", "Breakout", "Tetris", "centipede", etc. and add your own small twist to the design. Then once you start, punch yourself in the face every time you think about wanting to add a new feature (its a project management thing, not a crutch on creativity).