AMD stands for Advanced Micro Devices. They are Intel's number one competitor in microprocessing. AMD is currently the leader in CPU innovations and boot Intel down to number 2.
Their current line of CPU's are the powerful AMD Athlon 64 processor. They have different 'flavors' depending on what type of performance suited for you:
Athlon 64 FX (High performance CPU)
Athlon 64 X2 (Dual Core)
Server CPU's include their Opteron, and Opteron Dual Core CPU.
For overclocking, you don't need special hardware. You do it in the computer BIOS. Altering the HT settings, RAM timings are common in Athlon systems with Intel using FSB increments. Video cards can also be overclocked using RivaTuner and Coolbits for Nvidia cards. ATi cards, I have no clue. Risks involved are overheating. OC it too high, you risk overheating CPU and GPU (video card). Computer may lock up at high clocks too. Perhaps due to excessive heat build up or unbalanced overclock.
*Fact: Microsoft Window's Blue Screen of Death vs Computerforums.org's White Screen of Death. Which is worse?