Google's most famous blogger, Matt Cutts. Here's a link to search Google for all Matt Cutts' blog posts on SEO (although you may get some pages that simply have comments about SEO). Here are a couple of my favorite such posts:
Because search engines are always evolving, and black hat spammers are always trying new techniques to beat the search engines, white hat search engine optimization experts have to keep their fingers on the pulse of what Google thinks is black, white, or gray. Read Google's official opinion about SEO here.
Fuel Interactive is committed to white hat optimization exclusively.
Here are some superior sources for SEO articles and blog posts...