Generally hooking everything up is pretty simple. The hardest part is deciding where/how to mount the rad. When you first set it up in your case test it for at least 24 hours to make sure it wont leak and to bleed the air out of the system.
Do you plan to just cool your CPU with it or other stuff too (like video card, northbridge, etc). If you are just doing CPU you can probably get away with a single 120mm fan rad, otherwise you'll want at a rad that fits 2 120s if not 3.
Also, be sure to look up the pump that is shipped with the kit. IMO, almost all DC pumps are garbage, Eheim makes some good AC pumps that are suitable to be left on 24/7 (they are aquarium/fountain hobby pumps) and never dry run the pump.