From the wikipedia article on BDD:
BDD is a second-generation, outside-in, pull-based, multiple-stakeholder, multiple-scale, high-automation, agile me
The original article by Dan North about BDD may help: http://dannorth.net/introducing-bdd/
EDIT: Here's an article which breaks down each term:
http://cuke4ninja.com/sec_cucumber_bdd.html
In addition to the other answers, I have found the following links useful:
outside-in: http://www.courageousmarketing.com/pdf/outsidein.pdf
pull-based: http://www.johnhagel.com/paper_pushpull.pdf
I wrote a blog post on where I learned about BDD as couple of weeks ago. It focus on the .NET platform toolwise and is a bit Cucumber heavy since I like it, but you can pick out some BDD/ATDD stuff from there as well.
When it comes to articles and books I second the suggestions above - it's starts there!
But you should also checkout:
Well - there you have it. My short list for things to read.
Behavior driven development is similar to TDD software process but the advantage of BDD is that the tests/features are written in simple English language thus it give a chance to QA and stakeholder to participate in the process of development. It is focused on the behavior of the software thus test are run in browsers.
Here is the guide that explain BDD and its implementation very well. BDD Introduction and Implementation
You can use behat, browserstack to implement BDD in your development process.