Google Webmaster Central Channel on YouTube.
Uploading new videos as often as three times a week, the channel is quickly becoming a large repository of Google's current (and past) views on Search Engine Optimization.
Many of the videos feature Matt Cutts who (modestly) refers to himself as the 'head of Google's Webspam team' but factually has become the industry voice for the company on SEO-related and other issues.
Many of Cutts' presentations at conferences and internally can now be found on the growing YouTube channel. You'll find a few other Googlers there as well along with a behind the scenes look at Google Webmaster Central.
Google Webmaster Central was originally started by ex-Googler Vanessa Fox whose opinion and commentary can now be found on Danny Sullivan's Search Engine Land, another excellent resource for those who are new to the ever-growing online marketing landscape.
While I've never advocated 'do it yourself' SEO, the information on the slowly growing YouTube channel certainly can serve to see if your local SEO company is up-to-date with the latest advice and tips coming from Mountainview.
Correction 6/3/2009 PM: Google Webmaster Central was renamed Google Webmaster Tools last month. The new logo look for Webmaster tools is below: