[NEW BUILD] Need advice and suggestions

Hello Everyone,

I am building a computer for the first time and need some advice. I have been upgrading my old computer but it is pretty much at it's max. I only have a limited budget of around 600 dollars. I will be using my corsair 750 watt power supply as well as my geforce 550i video card for now.

Here is what i was going to go with, but if you know of better stuff for the price, I would really appreciate the advice.

Case:
Thermaltake Commander Series Commander MS-II Black SECC ATX Mid Tower Computer Case

CPU/MEMORY:
Intel Core i7-3770 Ivy Bridge 3.4GHz (3.9GHz Turbo) LGA 1155 77W Quad-Core Desktop Processor Intel HD Graphics 4000 BX80637I73770

Cooler:
CORSAIR Hydro Series H60 (CWCH60) High Performance Liquid CPU Cooler

Motherboard:
MSI Z77A-G45 Thunderbolt LGA 1155 Intel Z77 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard with UEFI BIOS

Approximate Purchase Date: First of the year

Budget Range: $600

System Usage from Most to Least Important: Gaming, surfing net

Are you buying a monitor: No

Parts to Upgrade: Everying but my power supply and video card.

Do you need to buy OS?: No

Preferred Website(s) for Parts: Newegg.com, or Tigerdirect.com

Location: Spokane, WA

Parts Preferences: by brand or type (e.g.: I would like to upgrade to Intel CPU)

Overclocking: Maybe

SLI or Crossfire: Maybe

Your Monitor Resolution: 1440x900

Additional Comments: I play WoW, D3, Assassins Creed 3, etc...

And Most Importantly, Why Are You Upgrading: Want a better gaming computer than my 4 yr old Dell XPS

Thanks for your help and time!