I'm a newbie too, but I'll tell you one thing, it's not going to be silent unless you do a BladeRunner
Personally, I put a DangerDen kit together from a Maze3 for the CPU, the GF4/9700 GPU block, heater core for the rad, an Eheim pump (1250 I think) and 2m of Tygon tubing. A couple of 120mm fans running at 5v gives the rig a very quiet noise floor but there's a problem...
... the damn hard drive. Jup, now that everything else is so quiet (the GF4 hsf was the loudest part in the case originally) I can hear the HDD loud and clear and it's not good. The WD1200JB I've got is loud in a metallic kinda way. For me this is worse than the fan noise I used to have even though it's quieter.
I'm looking into ways to reduce the hdd noise, but just be aware of that.