That list he pointed you to is the CPU support list for the board. That would tell you everything, actually.
Looks like a socket 754 board. Long dead. Single channel memory controller. Looks like 2.4 GHz (3400+) maximum. Overclock your chip to that.
I gave my socket 754 computer to my brother. He uses it for photoshop, autocad and internet. I've been through about three computers since then. He has a black thumb for computers and can kill anything made of silicon, but it's held up for 1 1/2 years for him, so it's durable. He also has lower expectations, so it seems like a rocket to him. In between now and then, there's been socket 939, AM2, AM2+, and now AM3.
So yeah - no new chips made for that for awhile. Single channel sucked anyhow - except for cheapness.