Hey guys I am attempting my first computer build which is actually more of an upgrade, I recently recieved an older pc and want to upgrade it a bit for gaming, I just want to be sure that everything I want to buy is compatable. The computer is a eMachines t3085.
I am considering PURCHASING:
Motherboard and cpu package
 http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=171512&csid=_22
Graphics card
 http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=7229011&CatId=3670
RAM
 http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=6753736&CatId=10
If ANYONE with any computer knowledge can help me out it would be greatly appreciated and also FEEL free to make suggestions on other things i should add but I am on a very tight budget so KEEP that in mind, thanks!What about the poser supply?I BELIEVE that the power supply is 480WMore importantly does the power supply have the expanded 24pin ATX power connector & EPS/ATX12V CPU power connector? Also any SATA power connectors?

Speaking of SATA power connectors I noticed that your motherboard only has 1 IDE connection (this is standard now). This means that if you are currently running on IDE HDD's and ODD's then you will have a problem.
RAM memory should be fine even if you buy two modules.
http://www.biostar.com.tw/app/en/mb/content.php?S_ID=495 (motherboard specification)

Graphics card is quite a dated one, I'm not sure that it will benefit your system due to the existing on-board graphics. Also according to passmark (and release years) you will get more bang for your money with an ATi Radeon HD 4550, they sell at about the same rate as your selected card. (ATi tend to give better value for money on lower end video cards than Nvidia)
http://www.videocardbenchmark.net/gpu.php?gpu=GeForce+8400GS
http://www.videocardbenchmark.net/gpu.php?gpu=Radeon+HD+4550

Again with the CPU you could get a little more out of an AMD Athlon II X3 425 for the same money but then you lose the motherboard that's on offer with your current CPU. Also it's hard to pick out a motherboard for other people due to the fact that motherboards are custom to the user (e.g. I don't buy motherboards with on-board graphics).
http://www.cpubenchmark.net/cpu.php?cpu=AMD+Athlon+II+X2+255
http://www.cpubenchmark.net/cpu.php?cpu=AMD+Athlon+II+X3+425

ODD = 'Optical Disk Drive' new abbreviation, deal with it