From my blog last year http://williambswift.blogspot.com/2009/04/web-is-still-not-adequate-for-serious.html

The Internet is the world's largest library. It's just that all the books are on the floor. -- John Allen Paulos

And

Most pages are very shallow; many others are too narrow for learning, though decent papers for those already knowledgeable in field for research. Too much emphasis on new results, but most new results are wrong, many of the rest are incomplete.

I also followed up, and discussed Robin's comments, including "Until you've read and understood textbooks, why bother with anything else?", in http://williambswift.blogspot.com/2009/04/overcoming-bias-and-learning-from-www.html