Some of the best resources on search engine optimization come from Aaron Wall’s SEOBook.
Aaron has written a very detailed article about the comparative value of a #1 ranking on Google’s search engine results pages. What is surprising is just how much of a difference #1 is.
If you want to learn about SEO in detail, then joining Aaron’s SEO community is a good investment. Great online book and tutorials as well as access to an extremely helpful SEO forum.