What clock speed values should I set to overclock my powercolor 4850?

Well, actually i haven't got it yet but i want to know what clock values to set for the card. I have never overclocked before, This is my first computer build, but i do know quite a bit on computers. I'm probably gonna build next week, that is probably the 20th November 2009. The card im gonna buy is PowerColor 512mb Play!. One more question, whats the Play! for? and in the catalogue(not an online one), it says PowerColor 512mb Play!(pcs w/HDMI $169) $189. The prices are not USD. I live in asia. ok so whats the pcs with hdmi? why is it cheaper????

To know which clocks are best for your card, you have to do trial and error. That means increase the clocks a little bit, and then test for stability. Keep doing it until the card starts getting very hot (Above 70-80) or you start seeing artifacts.

As for thermal paste, I recommend Arctic Cooling MX-2. I have used it on my 4850 and it idles at 36-39-36. Max is around 60 with 50% fan only. I have put another fan in front of the card's fan to feed it cool air.

GPu temperatures depend on your ambient temp, case air flow etc, so u wudn't want to set your clocks at the same speed as someone else's wthout testing stability first.

CCC has an OC program that works pretty well. I ran it and it set my 4850 at 690 (GPU) and 1190 (Memory). It bugged a little on Far Cry so I backed it down 20MHZ each and i seems stable now. Mine is the 1gig version of the XFX card. Prices on 4850,s should be dropping. Not sure you have ability, but newegg is good place to review cards and they have good prices paid 125.00 for 1GB. Sometimes they have them at 119,00 and less.
If you use the CCC Auto Tune be aware it takes a while to clock the card. I waited for about 45 minutes, then went to work. When I got home it was done. Also, some MB,s have a good OC utility. Have a ASRock that has a good utility. Not as good on my Gigabyte through.