If all you want to do is overclock your chip, you dont necessarily need watercooling. A good HSF might be able to get you to 1GHz if you've got a good chip. Of course you
are here which prob means that you're going to watercool no matter what
A basic watercooling system needs a waterblock for the CPU, a radiator, a pump, and maybe a reservoir. Currently it seems that
DangerDen makes the best water blocks, and
Overclock-Watercool (sold at caseetc.com) is a good place to get almost everything else.
I would recommend you get a DangerDen Maze2 Block, OCWC Black Ice Radiator, 250+GPH pump, and Water-Wetter and maybe Dye-Lite if you want it. The Water-Wetter keeps your system from corroding and lowers the freezing point of the water if you want to supercool. Dye-lite makes it all glow under a blacklight