I’ve written before about the power of Django – it’s the engine that underpins this website. A lot of my learning came from the main Django website here, but now there are a couple of books available.
The first one of the two is better – it’s written by two of the creators of Django and it’s clear, entertaining, and practical, with a lot of clarifying and thought-provoking examples. It’s also more current, although the authors wisely recommend that you check with www.djangoproject.com for the latest information.
The second book (published first, and referring to a slightly out-of-date version of Django) is broader, but it also covers another Python-based framework – Turbogears. This book is useful if your goal is to understand the kinds of things that web development frameworks are capable of, and to get a taste of a couple of modern examples.
If your goal is to learn about Django specifically, and perhaps to build a site based on Django, my recommendation is to start with the Holovaty book, and then go on to other resources once you’ve learned the basics. In any case, this book provides a lot of reference material that will be useful even when you’re an expert.