On Amazon the paper price and the Kindle price are about the same... ~$25 i think it is a dollar more for the privilege of not carrying 4.2 pounds around!

This book focuses on long-lived fundamentals; on helping readers learn how to think about solving problems and taking on new challenges; and on tools that don't change with the Drupal version.

That said, the book is not already outdated nor will be soon in the many version-specific tech details it does include; unlike many other books available it waited until Drupal 7 came out and it even was updated in the last hour to reflect the latest Views 3 user interface. This book is a solid foundation for years to come.

Disclosure: I'm an extremely biased source, and almost as familiar with the book as reviewer Michael Ross. Wow, i wish he had been the copy editor.

If your code is PHP, and considering what it's strengths are (the forum display and experience rather than the user registration management, for instance) you may want to look into converting it to a Drupal module and releasing it-- rather more likely to have a user and a developer community this way, though it would be a lot to learn for just one project.