This makes me wish I wasn't already a Rails dev so I could have the pleasure of learning from scratch with this series. Anything Gregg Pollack screencasts is worth absorbing.

His initial http://www.youtube.com/user/envyads#p/u (with Jason Seifer) practically invented rails evangelism. Then his many videos on Scaling Rails (http://railslab.newrelic.com/scaling-rails), Rails 3 (http://rubyonrails.org/screencasts/rails3), and other topics (http://envycasts.com/) are awesome, informative and entertaining. And no, I'm not paid to say this :).