If you know know anything about electronics you can install a car radio easily. It isn't a totally free installation cause you will have to buy a dash kit and wiring harness. Me personally am not a fan of best buy radio installs and here is why:
They say that you have to be trained and certified technician to install a car radio..bullshit, if you had to be it would say in the installation manual.
The use crimp connections. Soldering is always the best option.
They will sell you that extended warranty. If you can install a car radio correctly the first time a good brand of radio should last a long time. Also they will say they will take it apart and clean the radio...most of the punk kids who work their do more harm than good when taking apart...
Here are some options for you to do:
Go with crutchfield (
www.crutchfield.com ) they will give you a free wiring harness and dash kit and full instructions for your vehicle.
Buy a radio off of ebay and then buy the dash kit and wiring adapter from best buy. You can save about $100 on a radio compared best buy.
This is all just my $.02