Could you recommend some resources for learning BDD?

Sure. Now that I'm not on my phone, it's much easier to grab some links.

Here's the original work on the subject, by Dan North: http://blog.dannorth.net/introducing-bdd/

A little Rails specific, but this post by Sarah Mei is pretty awesome: http://www.sarahmei.com/blog/2010/05/29/outside-in-bdd/

These two Railscasts on Cucumber are good: http://railscasts.com/episodes/155-beginning-with-cucumber http://railscasts.com/episodes/159-more-on-cucumber

But really, conceptually, BDD isn't that complicated. The hardest bit is figuring out the tooling for whatever language you're using, getting comfortable with it, and practicing. I know the Ruby side of this well, but if you're using another language, I'm not sure I can be of much help.

Adding on to your comment, a friend let me read through a beta copy of The Rspec Book last year. At the time, only the first couple chapters were written and it was lacking a lot of content. It was a great resource though, and I would highly recommend it. The final release is due "Soon", and ordering it now gives you access to the current revision of the Beta, which I hear is complete sans-editing. I'm holding out until I can buy a paper copy.

http://www.pragprog.com/titles/achbd/the-rspec-book

Your links to the RailsCasts screencasts are great also. PeepCode also has their Cucumber Screencast that is a little more detailed than RailsCasts.

http://peepcode.com/products/cucumber

These are all Ruby or Rails specific. Cucumber itself is a DSL to be used along with another language, and there are projects underway to implement Cucumber or Cucumber-like frameworks for other languages like Python, Java and .NET

Thanks. I almost linked to the RSpec Book, but since I haven't read it myself, I didn't feel comfortable endorsing it. Good to know it's shaping up! Maybe I'll have to pick up a copy.