Maximum PC

Hi!
I decided to build my first PC over the next few months. I spent the day picking/choosing all the products that are needed to build a pc. I am somewhat new to this and I am not sure, if you need certain products to match with one another, like a puzzle. I would also like to know if I can upgrade any of these at anytime or if I upgrade one thing, would I have to upgrade something else?

Here is my list: http://www.amazon.com/gp/registry/wishl ... av_lists_2

Tower - Cooler Master Elite 430 - Mid Tower Computer Case with All-Black Interior (RC-430-KWN1)
CPU - Intel Core i3-2120 Dual-Core Processor 3.3 GHz 3 MB Cache LGA 1155 - BX80623I32120
MOBO - AS Rock LGA1155 Intel Z77 CrossFireX SATA3 USB3.0 A GbE ATX Motherboard Z77 PRO4
Video Card - MSI N560GTX-M2D1GD5​ Video Card
RAM - G.SKILL 8GB (2 x 4GB) Ripjaws X Series DDR3 1600MHz 240-Pin PC3-12800 Desktop Memory F3-12800CL9D-8G​BXL
Hard drive - Western Digital Caviar Blue 500 GB SATA III 7200 RPM 16 MB Cache Bulk/OEM Desktop Hard Drive - WD5000AAKX
Power Supply - Antec VP-450 450 Watt Energy Star Certified Power Supply
Internal Drive - Samsung SH-222BB/BEBE 22X SATA DVDRW Internal Drive (Black), Bulk without Software

Keep in mind all these products are in my price range. I plan on using this computer for everyday use (I only play games like League of Legends and Diablo 3). If there is any recommendations or if this is a fine built that would be great.