Ok, so my Komputer is going along well as far as parts.
I am sort of on cooling the CPU.
I came across many FANS and have an idea on what I want to use but what about that thermal paste?
Is SILVER thermal PASTE necessary?

What are you buying? Stock cooling is just fine for most people.

I am going to buy an E8400 3.0GHz.

Are you planning on overclocking?

You will need to use thermal paste but it doesnt have to be silver based, although most are. If you really want to learn all about it checkout some comparisons like: http://benchmarkreviews.com/index.php?option=com_content&task=view&id=138&Itemid=1

You don't need thermal paste. The phase changing pads that come on stock heatsinks are just fine. In fact, they outlast most compounds by a wide margin. I've heard people say "yeah Arctic Silver may not be that much better but it doesn't dry out like the white stuff." Bull****. Silicone/zinc dioxide pastes never dry out. I have taken apart electronics from the mid 1980's that still have white paste on there fresh as they day it was put on.

AMD actually covered all of this in a whitepaper, wherein they recommended various thermal interface materials. Fancy overclocking ones were no where to be found. Because they suck.

Oh and, the best stuff is probably this. It's an alloy of indium, copper and bismuth that easily melts with the heat of the processor. It turns to liquid and fills the gaps, and being all metal, conducts heat better than anything else. And it lasts forever, too.

Good suggestion especially since its almost impossible to mess up an install using precut thermal pads. I have seen some people apply way too much thermal paste to the cpu which defeats the point.

Wait, is it even necessary to have this thermal paste/ phase changing pad?

Yes.

Otherwise, the heat will fuse your processor to your motherboard and you will have to replace them both.

Uh. No. Not at all. It just runs a lot hotter. With an efficient processor in a cool environment, it will even run at acceptable temperatures.

Just use the pad that comes stuck to the stock heatsink, and use white thermal paste if you ever need to reapply the heatsink.

WATCH OUT ARCTIC SILVER BURNS YOUR SKIN IF YOU TOUCH IT YOU'LL HAVE TO GO TO THE ER TRUST ME IT HAPPENED TO A FRIEND TRUE STORY

I assumed he was talking about the pad that came with the processor too?

You need to have some sort of thermal compound to fill up the microscopic air gaps between the heat sink and the processor. Air is an extremely poor conductor of heat. Thermal compound is orders of magnitude better, but also orders of magnitude worse than solid metal. So for better or worse you have to use something, you just have to be careful not to use very much.

As a minor aside, my GPU overheats really really ridiculously easily (like at 60C which is stupid low). I've got a 7900GT and it runs ~50-55 sometimes (when the ac is up) and othertimes it overheats like mad then shuts my computer off.

Despite removing the hsf and applying thermal paste multiple times with multiple densities it seems like there's just no heat transfer. I tried Arctic Silver (came with my processor) and have some ****ty radioshack ceramite paste laying around. Should I try this? Will it work better?

The HSF is admittedly bad but it shouldn't be doing this at stock (or even underclocked) speeds for any reason.

Yeah, didn't feel like making a new thread.

I don't have any solution between the hsf and gpu and it runs 60 degrees c

That's strange, I frequently ran my X1650XT at 80C and it was and still is fine. It sounds like you might have some kind of thermal shutdown enabled.

I have overheated my 7800GT (overclocked) as well. I think the stock fan is poorly designed, too much crap accumulates in it. Blowing it out with compressed air seems to last a few months before it clogs again.

No, it starts artifacting and then shuts down. Like bad artifacting. I'm thinking it's a problem with the sensor not reporting correctly, but regardless I want to see if I can't minimize the amount of artifacting significantly.