OH, and the last thing you would need is a sub, you could look inexpensively at the Polk PSW10 its about $125 shipped, it wont go very low, but for a starter system it should do fine. You can get this at newegg.com or Amazon.com
The other sub to look at would be the Premier Acoustic PA-120 for $229 I think the website is sounddistributors.com or google it.
Lastly, you will need to get speaker wire, in-wall rated if your going to use those spots and run the wire in the walls to the outlets, unless the wire is there for you already.
You will also need 2 HDMI Cables, and a Subwoofer cable for the sub.
All this can be purchased inexpensively at
http://www.monoprice.com/home/index.asp