Flyerm14 - Gary, Rob and the other folks here have great experience to share with you. I've recently been in your shoes (as a neophyte), so I'll relate my best sources of info for the same decision.
This forum is my favorite, by far. However, also visit the following:
http://www.ar15.com/ - this is an excellent source of information. Don't miss the AR forum they have there. It is an entire forum dedicated to AR's, with areas devoted to the different manufacturers, components, tactics (oops - hey there Kodiac
) and so on. They also have a discussion on the 'perfect' AR, all the magazines available, ammo, and on and on. Also, links to the manufacturers - check them out.
http://personal.cfw.com/~hayslett/guns.htm - AR information and links.
http://www.geocities.com/Pipeline/2494/ - AR-15 / M-16 links
AR15.Com also takes polls (unscientific, although I doubt there are many people staying up nights working to distort them), and they give you some idea of what others like and don't like. Colt and Bushmaster seem to garner the most respect, albeit at a higher price.
The advice I received was that Bushmaster was producing some of the highest quality rifles at this time - supposedly Colt had declined in quality. YMMV. Building your own seems also to be a popular option.
Good luck. Adios.