"Also be sure to get your ebooks and literature not only without DRM, but also in a free format, preferably EPUB. While PDF is also free, it is less ideal for ebook viewing, reflowing, and editing. The sites listed provide files unencumbered, but it's important to be mindful that both of these can still contain DRM elsewhere."
Full Circle is a free, independent, magazine dedicated to the Ubuntu family of Linux operating systems. Each month, it contains helpful how-to articles and reader submitted stories.