If you're using django, there's a chapter in the Two-scoops of django 1.6 book that covers django security. Have you looked into framework specific resources? If you're using one of the big ones, this may be the most practical place to start.
Nikto, and other free web app vulnerability scanners can be good for both learning and practical use in the real world (albeit not much more useful than low-hanging fruit). http://sectools.org/tag/web-scanners/