It's literally plug tab A into slot B. Plus there are a lot of great advice from the Tech Thread that is linked by BarretsFloyd. They helped me out a great deal. I got a lot of the step by step from the amazing tutorials from Newegg. In fact I got a better deal and purchased everything from the case to the components to the KB&M to the cables down to the wire ties.
If I can figure out how to do it I know anyone else can.
If you have the money, it's better to get it now. Some will say... "Wait a couple of months and super x part will be available and the current part will be cheaper." Forget that. I mean if it's a week or something, maybe. Otherwise, you will never get into anything as you will always be waiting for the "next big thing" to cut the price of the current.
I had the opportunity to get the new i7 processor and was told repeatedly... "you don't need that". So, I settled for the i5. 6 months later I wished I had spent the extra $150. The same for my video card.
I spent 1200 for my set up and I wished I had spent another 300. I don't use my rig just for games, so don't listen to idiots that scream out "That's crazy just to play games". My rig replaced my entire entertainment system and that includes my cable box. The point is... you will use it for more than just games.
It's not a "gaming PC". It's a powerful computer.
There are a lot of gamepads to choose from. My wrists cannot take more than a few minutes with that mouse and the keyboard is just too clunky and I end up hitting the wrong key.