There are also some screencasts scattered around the Heroku blog. For example, I was just using their screencast on New Relic and the queue depth:

http://blog.heroku.com/archives/2010/3/8/heroku_casts_queue_...

I also recently used another screencast for setting up a Sinatra app. It's incredibly simple, go figure:

http://twilio.heroku.com/

Very helpful. The Heroku docs also have a lot of information about the Heroku specific stuff that you might want to read about (like dynos and the backlog).