-using my own ram and HD, have a DDR3 4gb stick, and 2 2gb sticks, and a mechanical type HD.
This is my first time attempting to build a computer by myself, here are my questions.
Is everything compatible? Do you notice any problems that might occur with these parts?
How "good" will this computer be for gaming? Do you think it could handle high settings on BF3?
I am nervous about building it, I really don't know how to yet, I am going to watch some videos including the newegg one. Could you recommend some other resources / have any advice on to deal with first time building?
It's recommended not to mix different RAM kits. All compatible, and BF3 will run at 60FPS at high, 45-50 at Ultra. Newegg videos are really good, but just Google "How to build a computer" and you'll get a ton of guides.