If you’re creating ePub files with QuarkXPress, you’ll find some great resources for ePub files in Quark’s free QuarkED collection here.
Module 15 on Digital Publishing is especially helpful:
Jay Nelson is the editorial director of PlanetQuark.com, and the editor and publisher of Design Tools Monthly. He’s also the author of the QuarkXPress 8 and QuarkXPress 7 training titles at Lynda.com, as well as the training videos Quark includes in the box with QuarkXPress 7 . In addition, Jay writes regularly for Macworld and Photoshop User magazines and speaks at industry events.