Advice on a good motherboard

Hi all. I am currently in the process of getting a list together to build a mid range gaming machine. I only play the first person shooter games ie Call of Duty 4, brothers in arms. The rest of the time the PC is used by the teenagers (ie facebook etc). A friend bought a EVGA Ge Force 8800GTS video card and he soon realized he could not get it in the pc he has. So I now have it. I have the DVD drives, power supply(600w) Hard drive etc picked out(not purchased yet tho). What I need is advice on is a good MB, AMD Athlon 64x2 processor (friends swear by these for gaming?). and a case that will house everything. That video card is massive.(2 slots). I prefer to purchase from either tigerdirect.ca, or newegg.ca (I am in Canada). Thank you for your time and the help. jim