AMD makes four types of sockets, socket A, socket 754, socket 939, and socket 940. I'm pretty sure the semprons and older Athlon 64s run on socket 754, the newer 64s run on 939, the Clawhammer cores and FX series run on socket 940, and the Athlon XPs run on socket A, although I can't remember exactly.
Most new motherboards today I believe should support AMD up to 5000+ or FX-59.