I would like to create a 2D tile based point-and-click type multiplayer online rpg . For the most part I feel pretty comfortable with it, I have quite a bit of experience with making 2D games.
Now to be clear I'm only expecting to build thebare bones of a MORPG, and I don't have any grand expectations for it to be a serious game. It's really more of a learning experience for me as it's something I've always wanted to create.

I am completely new to the concept of programming databases and servers and all that jazz. Are there any really good tutorials for beginners all the information needed to set up the bare bones of a multiplayer online game?

My game will be made in C# and XNA so if the tutorials were made specifically for that, it would be even greater.

Also what kind of hardware is necessary? How good of a computer would I need to run the server? And how many players could an average computer handle logged in at once? Not that I expect there to be a great many people playing this game, but these things are nice to know.

Are there any things someone needs to be aware of when taking on a project like this? I'm sure there's much I've overlooked.

Also do you think XNA is a viable resource for building an MORPG? Are there examples of other people taking on projects like this? If there was a community of XNA developers with similar interests I'd like to get involved with that.

If you're comfortable programming 2D games already it shouldn't be too much of a leap to create a server. Lookup socket programming and start by creating a 'echo' server or something similar.

As for hardware, you don't need anything special at first. Written correctly, a laptop is a good enough server for up to several dozen connections if not even more. The tricky part is when you want to officially host your server. You'll need an ISP that allows you to run your server process and have it listen on your specified port(s).

If you haven't done multiplayer games, and you haven't done persistent games, you shouldn't try to learn both at once.

Performance is best measured with the code you're going to use.

I agree with this. You should not try to work with client/server architectures and using a database all at once. My advice would be to start with a simple chat and see how far you get with that.

I would be quite tempted to experiment with Google App Engine (or other similar service) https://developers.google.com/appengine/.