Post Mainstream Resources Here
 

A few off the top of my head:

http://www.jensense.com
great resouce on pay per click programs

http://adwords.blogspot.com
the official adwords blog

http://adsense.blogspot.com
the official adsense blog

http://www.sewatch.com
the daddy of SEO sites

http://www.seoresearchlabs.com
good free SEO download

more to come.

post yours