Hey, I'm a first-time builder, and I just have some questions about what components to get.

1. How many watts do I need for my power supply? I know there are calculators for that online, but I'd rather get a rough estimate from a human. I'm getting an Intel Core 2 Duo E8400 - 3.0GHz, 8GB of memory (4 DIMMS), one 7200 rpm hard drive, a GeForce 9800GX2 with 1GB of DDR3, and a Sony DRU-V200S/BR DVD Rewritable Drive. I'm also probably going to buy an extra heatsink, though I'm not sure which one yet.

2. Do I need liquid cooling? First off, is it only cooling the processor, or other things that produce heat as well (are there other heat-producing parts to worry about?). Are liquid cooling systems only for extreme overclocking? How much would I have to overclock my processor (mentioned in #1) to need a liquid cooling system?

Thanks.

The graphics card you have listed is power hungry, and is the largest determining factor when it comes to choosing a PSU for this build. If you are going to only be running one card you will need a minumum 600W PSU, if you are going to run two you will need a 850W PSU. I would stick with one of the better manufacturers for this purchase, like PC Power & Cooling, or Antec.

Those that use liquid cooling are usually overclockers. On most builds a good CPU heat sink and fan will be adequate. Another source of heat is the graphics card, these can run hotter than the CPU. One consideration would be if you are going to be running two graphics card, you may want to look for a motherboard which will have the CPI-E X16 slots split with one or two PCI slots in between allowing room for good ventilation.

I would suggest an 850W PSU.
Water cooling is pretty much a waist of time and money. they do cool other things besides the cpu but you have to buy either a special component made for water cooling or a special adapter to fit each component. air cooling technology has come a long way in the past few years and is just as good and much much cheaper. get a good heat sync and fan and a hard drive cooler and expansion slot cooler for your graphics card and a couple case fans and you will be good to go.

as far as how far you would have to overclock to need a water cooling system. it's hard to say. i have a 2.8Ghz dual core running at 3.4 with a copper heat sync and fan and it is just as stable as can be.

hope this helps.