New to computer building

[Mr_Squirrel]

Hey, I'm looking for some help in upgrading my old computer. I just bought the game Assassin's Creed and was very disappointed when my computer wasn't fast enough to play it. I was wondering if you guys could refer to me some good parts for my computer that are at fairly low prices. I want my computer to be fast enough where I won't have to upgrade it again for a few more years. I also want to be able to play any games I buy in the future, but it doesn't necessarily have to play them at the absolute best quality.

Currently I need a new:
-CPU
-Motherboard
-video card
-power supply
-and more memory

Any suggestions or advice you guys could give me on building my computer would be greatly appreciated. Thanks.

 

[dirtmountain]

Tough to work without a budget or at what resolution you'll be playing at.

Start with a E8400 CPU at $165
http://www.newegg.com/Product/Product.aspx?Item=N82E16819115037

drop it in a Asus P5Qpro P45 motherboard at $105 after rebate (will run crossfire at 8x/8x)
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131299

An Antec EA Earthwatts 650w power supply at $65 free shipping (will support crossfired 4850s)
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371015

GPU - Asus HD4850 OC $140 after rebate. Get another one now or later.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814121272

RAM - 2x2 GB DDR2 800 1.8v $48 after rebate
http://www.newegg.com/Product/Product.aspx?Item=N82E16820146731

$475 after rebates with one HD4850

 

[Mr_Squirrel]

Hey thanks. My screen resolution is 1024x768 and my budget is a little below what you gave me. I was originally planning on spending less than $400 but if I have to I'm willing to go over if it means that I will have the computer I want. I understand how hard it is to make a good computer on my budget.