If you're looking for a simple primer to web analytics, especially Google's, look no further than the acclaimed Occam's Razor blog and in particular this post that distils analytics down to the 5 basic tenets:
#1 Get the Basics Out of the Way.
#2 Understand Traffic Sources.
#3 Fix Stuff and Save Money
#4 the value of using the Site Overlay
#5 Focus on Outcomes