As you can tell from the title it's the first time that I'll be building my desktop with gaming in mind. I bought it a few weeks ago as it was on sale and it was far better than the previous one I had been using (it was about 6-7 years old). What I'll be looking to upgrade form the get go is the CPU and GPU in order to run games at a fairly high quality but as I don't have a lot of experience I felt it'd be best if I sought advice from people that do before I went out and bought something that turns out wouldn't work.
From the information I've gathered about it the motherboard is 'ASUS P8H6-M Lx2', it has 1 stick of 4GB RAM, the graphics are currently on board and the CPU is dual core 2.8 GHz and the socket is LGA 1155; I'd get more info about the CPU but I'm currently waiting on some thermal gel to apply it when I'm replacing it.
I've looked at some GPUs that I assume would be viable for gaming on the machine that are in my budget such as a Radeon HD 7850 (If you know it's not then please let me know); I've heard from some places that for games running @ 1360x768 it'd be overkill but I'd take it as being fairly future proof, at least for a little while.
As for CPUs I'm not entirely sure what'd be viable so if anyone has a recommendation I'd like to hear it.