So I'm looking to get a desktop and instead of just buying one outright, I was thinking of building one since it would offer more flexibility. Unfortunately, I've never done this before, so I figured I'd ask the Kotaku community for help and examples of their rigs. I've been using the Lifehacker guide to get a better idea of the components, but my biggest fear is buying a part only to find out that it's incompatible with everything else. I've been looking at this combo from Newegg as a less complicated alternative.

I'm not looking for anything high-end but I'd like to be able to play my Steam backlog and games like X-COM on decent settings. My budget is around $500 - 600. Anyways, any help would be much appreciated!