Dilbert's Philosophy on SEO
A Good content site that with Small Changes that will improve SEO and a good content site with Great SEO and two make overs (hair and Personal Budgeting sites).
Beware of Black Hat SEO or stupid tricks & what happens to Black Hat SEO sites
Google's Report on its own SEO!
Google Changes the SEO algorithm daily and major updates throughout the year but they have standard guidelines that you should follow that will help you improve your SEO