Hey guys I've been wrestling over the idea of building my own computer or buying a completed one, I probably would build my own but I have no idea on where to start or go to purchase parts?

I'm going to be running a duel monitor setup w/maya 5 unlimited and all of the image editing software and compositing software, I'm going to be doing freelance work, also what is a really good operating system? I want to be able run and burn dvds and run internet and maybe a few games.

Also is there any good sites on how to put it all together and build it?

Thanks for the help guys