Dmitry Popov released an e-book covering tips and tricks of using digiKam, a free photo management tool for KDE.

The book is currently available for Amazon's Kindle only, but you can convert it to anything using Calibre.

The author gives 50% of all book sales to the digiKam project, and the content is available under the Creative Commons BY NC SA 3.0 Unported license which makes it legal for you to share it once you bought it and indirectly sponsored the project.

More on this topic:

• GIMP 2.6 for Photographers
• GIMP 2.6 Cookbook by Packt Publishing
• First ebook on MuseScore for beginners available
• First darktable e-book released
• digiKam 2.1.0 released with panorama stitcher