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.
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.
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.