You can look at all sorts of setups and read up on what parts they consist of, lots of people have articals of their water cooling builds, reviews, remade sets you can buy,etc.
I believe however you should only need:
Resivour to hold water, mounted in 1 or 2 5&1/2" bay depending on how big you choose (this is a container that holds water, but why its important is it lets air rise to the top of the container so that only fluid is sucked into the system, inlet hose in the middle of it, outlet hose on the bottom, air rises to the top of the container)
Radiator /w Fan attached
Pump
Hoses that fit radiator and waterblock inlet/outlet sizes
Waterblock(s) for cpu, north bridge, video card, ram, etc
Distilled water and perhaps some water wetter. Thermal paste under the waterblocks on top of the chips.
I always wanted to buy a car radiator cheap, maybe with a car fan too and hook up a vairible resister to control its speed/audible level, then mount it on the other side of the mobo tray, run tubes up through the top of the comp down into the water blocks, with a pump inside too.
