Also, be sure to get a wiring harness adapter when you install the HU (they make adapters for the speakers, too). That way you can wire the adapter to the HU and then just plug the whole thing into the stock harness.
For wiring, a lot of people recommend soldering the wires and then covering them with shrinktube. That's nice but it's a giant pain in the ass and if you aren't used to soldering, you can easily get cold solder joints. When I installed professionally, we used "snowcone" crimp connectors.
http://www.amazon.com/Install-CCL161..._bxgy_hi_img_y
Just make sure you have crimpers with the little tit in them and not the ones that just squish the connector.
http://www.amazon.com/GB-GS-388-8-In...ywords=crimper
We never had any fail.