Need help building a gaming computer

[xdumbnameherex]

This is the first time that I will be building a computer, so I am new to this kind of stuff. Any comments on individual parts or corrections to compatibility issues would be greatly appreciated.
Currently the monitor I am using for this build (already owned) has a 1440x900 resolution. May plan on upgrading the monitor in the future.
I am looking to build this computer to play games such as WoW, SC2, Dragon Age Origins, and Diablo 3 in the future.

Intel Core i5-750 Lynnfield 2.66GHz LGA 1156 95W Quad-Core Processor Model BX80605I5750
Newegg.com - Intel Core i5-750 Lynnfield 2.66GHz 8MB L3 Cache LGA 1156 95W Quad-Core Processor

GIGABYTE GA-P55-USB3 LGA 1156 Intel P55 USB 3.0 ATX Intel Motherboard
Newegg.com - GIGABYTE GA-P55-USB3 LGA 1156 Intel P55 USB 3.0 ATX Intel Motherboard

Western Digital Caviar Black WD6401AALS 640GB 7200 RPM 32MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive
Newegg.com - Western Digital Caviar Black WD6401AALS 640GB 7200 RPM 32MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive

CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 Power Supply
Newegg.com - CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 Power Supply

G.SKILL 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10600) Dual Channel Kit Desktop Memory Model F3-10600CL8D-4GBHK
Newegg.com - G.SKILL 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10600) Dual Channel Kit Desktop Memory Model F3-10600CL8D-4GBHK

COOLER MASTER HAF 922 RC-922M-KKN1-GP Black Steel + Plastic and Mesh Bezel ATX Mid Tower Computer Case
Newegg.com - COOLER MASTER HAF 922 RC-922M-KKN1-GP Black Steel + Plastic and Mesh Bezel ATX Mid Tower Computer Case

XFX HD-577A-ZNFC Radeon HD 5770 (Juniper XT) 1GB 128-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFireX Support Video Card
Newegg.com - XFX HD-577A-ZNFC Radeon HD 5770 (Juniper XT) 1GB 128-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFireX Support Video Card

ASUS Black 24X DVD+R 8X DVD+RW 12X DVD+R DL 24X DVD-R 6X DVD-RW 12X DVD-RAM 16X DVD-ROM 48X CD-R 32X CD-RW 48X CD-ROM 2MB Cache SATA 24X DVD Burner - Bulk - OEM
Newegg.com - ASUS Black 24X DVD+R 8X DVD+RW 12X DVD+R DL 24X DVD-R 6X DVD-RW 12X DVD-RAM 16X DVD-ROM 48X CD-R 32X CD-RW 48X CD-ROM 2MB Cache SATA 24X DVD Burner - Bulk - CD / DVD Burners

Another question I have is will I be able to do any kind of overclocking with this build? I wouldn't plan on doing anything crazy, and it would be more for learning than anything else.
Also in comments on the gaming potential of this computer would be appreciated, currently I am playing on a Toshiba Tablet Portege M750 with Intel Core 2 Duo Processor, so I am feeling that this build will already be enough to blow my mind.

Thanks

EDIT: Didn't realize there were two forums, one for high performance and general, don't really know if this qualifies as high performance, sorry

 

[Slaymate]

This memory is only a little more cash to start with but after the rebate it cheaper, best of all it's faster
Newegg.com - OCZ Gold 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Dual Channel Kit Desktop Memory Model OCZ3G16004GK

You'll be able to overclock the system a little with the stock heat sink but you'll want to invest in a better one for any substantial jump in clock speed.

 

[Sean W.]

what kind of things are you planning on doing with this new computer? gaming, video rendering? what kind of games do you want to play... and most importantly what is your budget?

 

[xdumbnameherex]

To Sean W. - I am looking to build this computer to play games such as WoW, SC2, Dragon Age Origins, and Diablo 3 in the future.
EDIT: My budget I haven't really determined yet, I was working on a build with an i7, but it just seemed like it might be more than I need for the price (was about $400 more than this $800 build)

To Slaymate - The ratings for the memory you suggested are kind of scary, although most of the problems reported seem to be a mislabeling of the product as 1600 instead of 1066 which even then I think would be ok for my setup, so i guess I'll take your word for it, thanks.
Also yea, I would definitely add an extra cooling device before I attempted to overclock.

 

[CalcProgrammer1]

The OCZ Gold is 1600 memory but it is factory set at 1066. OCZ claims this is for "compatibility reasons" but you will have no problems running it at 1600 if you just manually set the speed in the BIOS. I have the OCZ Gold Triple Channel kit (3 of those sticks instead of 2) and after upping the speed to 1600 it runs fast and works well. Best part is it runs at 1.5V, so I can run it cooler and under less stress than the rated 1.65V.

 

[VishKapish]

If you're talking about the newegg ratings, don't listen to them. Most of the people don't really know what their talking about. For example, the triple channel kit has much higher ratings then the dual channel, even though there's no real difference in the actual RAM. OCZ is a solid brand so you don't have to worry about the RAM being unstable at 1600.