Canonical Link Element (Google webmaster Video): Matt Cutts of Google introduces the canonical link element
Resources:
Blog post on Google webmaster blog:
http://googlewebmastercentral.blogspo...
Google Webmaster Tool Tips and Tricks
Best From Google
Adsense Tips and Tricks
Speeding Up in a Slowdown Google Videos
Guide and Tips For Bloggers
Twitter Tools
Social Networking Tools
Useful Tools and API's