I'm going to be building my first computer within the next 2 months and I would like it to be under $400. I know nothing about building computers so I don't know which parts to buy and if they are compatible. I do not need a mouse, keyboard, or monitor and I would like it to be upgradable. I want to be able to play games on it like Skyrim etc. but I don't need it to be able to run max settings. Also, any tips to building a computer would be nice 
