1. I thought it would be a good idea, for practice sake, to record some generic sort of assets
2. for people to use for free. Post in on a site like freesound.org or some such.
3. I don't quite feel confident enough to commit to a project or team yet, so I just want to create some stuff and get response from people to see if I'm headed in the right direction.
4. I just want to know, what assets should I create?

1. Yes. You should absolutely be doing the thing you want to do. You need to build a portfolio, and network.
2. I don't know about that part. May be a slippery slope.
3. You need to get past that, and quickly. Get together with some amateurs and do a project. Like other students at your college. Which raises the question: got degree? In college? Planning to get degree?
4. Why don't you just listen to some games? Think about what kind of games (a) you want to work in, or (b) your likely customers will be working in. Regarding that latter: don't bother with the hopeless MMO projects; go for the amateur teams who are making realistic browser games or mobile apps.

Good, you're on a good track. This will take time. You don't have to wait to start building your portfolio.

Many would tell that creating a generic Sound Effects portfolio is a pain in the... I don't have one myself, just few random sounds to show what kind of quality devs should expect. It's not anything shiny or jaw-dropping, by no means professional, but before I managed to make one, I was lucky enough to get into few projects as a composer and I was offered to make SFX as well.

There are loads of simple beginner projects/games you can get into, that (even if fail to be released) would give you a good base or theme to create your first portfolio assets. The question is: What is the cause of you not feeling confident enough?

If you'd insist on creating raw assets, in my opinion general Foley is a must and the rest is (like Tom here wrote) whatever you or your desired clients aim for, stuff like Sci-Fi weapons, melodic cartoon sounds, or car engines.

I also wouldn't say that freesound is a good idea. If anything, I'd upload them to Royalty-Free marketplaces like AudioJungle as sets or single sound effects. You can start creating your 'brand' there, and if you are unsure about the quality, each file is carefully checked and priced by reviewers before being placed into marketplace. Usually a good feedback is given if the file doesn't meet the standards.

Do not give your stuff out for free - it creates a bad, unrealistic impression that audio content has little to no value. Charge something - even if it's only $1 per sound. Tie some kind of tangible value to your audio work. To work for nothing simply devalues our craft and undercuts the rest of the industry. (Yes, believe it or not even the actions of folks just entering into the audio industry can have ramifications all of the way up.)

To practice the art of sound design I would begin creating sound design for video clips of video games and trailers. This creates useful practice materials and could give you some demo material that you could share with potential clients. Note: Be careful when working with copyrighted material however. Make it very clear that this is solely for practice/promotional reasons and that it isn't a part of the official project or product. Even with that - however - it's hard to know how companies will respond given the whole SOPA/PIPA drama and such. It might be best to only share the master audio track of the sounds you created publicly and only share the video/audio version privately.

While you're creating these sounds do an A/B comparison where you see how well your audio stands against other professional audio for similar videos. I would advice against referencing the same video you're scoring because it could influence how your sound effects come about. Instead try and see if you can score a gameplay video of something you haven't heard - that way you could potentially come up with new, fresh approaches to certain gameplay elements.

Thanks,

Nate

Nate makes some great points.

I totally agree about the payment thing, unless you work something out with a specific team or group. One great way to get going might be to contact some projects that are already in the works, and ask them to put you in touch with their audio guy. Ask him if he needs any help so he can get your feet wet. It'll be kind of like an internship, and he might be able to unload some of the easier work to you. This would give you some good practice in a real environment, without laying the weight of the world on you right as you begin. It also builds some networking opportunities between you and other designers, which can be your most important ones down the road.

And while doing sound to an existing clip is always a great way to practice, my portfolio admission to my school was a sound only piece, kind of like a radio play. Come up with a short story on your own, and produce it using only sound. It's a great tool to help your chops, as well as giving you something to show off that's totally yours. It's also a good way to hone your storytelling skills, which I think is one of the most important things a sound designer can possess.

Best of luck!

To practice the art of sound design I would begin creating sound design for video clips of video games and trailers. This creates useful practice materials and could give you some demo material that you could share with potential clients. Note: Be careful when working with copyrighted material however. Make it very clear that this is solely for practice/promotional reasons and that it isn't a part of the official project or product. Even with that - however - it's hard to know how companies will respond given the whole SOPA/PIPA drama and such. It might be best to only share the master audio track of the sounds you created publicly and only share the video/audio version privately.

I'd like to add few words on that.

I actually contacted some of the copyright owners to ask for permission on publishing their videos with changed audio some time ago, mostly trailers/game intros for top shelf titles. The answer in all cases was simply no. That was due to fact that any kind of such material was - at least in those cases - made by 3rd party companies, with exclusive copyrights for whoever owns the rights to distribute the game content.

Nevertheless, actually the best way I found was to record gameplay videos and swap audio within them, or just use anything that's under Creative Commons Attribution.

Nate, very very wise words. There are so many composers working for free (usually just for fun, while they work on other things)..

But music can be a profession and you need to earn a living. This was really different ten years ago. Now things are very complicated.