Ruby is a good choice and is similar to Python. However, if you do choose Ruby, I would recommend starting out with Sinatra instead of Rails. Sinatra is simple and easily understood so it makes a good starting point. Rails does a lot of things by 'magic' so it is a lot more difficult to start out with.

http://www.sinatrarb.com/

On the other hand, if you do go straight into rails, this is the best rails tutorial I have found:

http://railstutorial.org/book