There is plenty of guidance for all aspects of using the EPUB standard
- Publishing@W3C. The W3C has a number of community and working groups dedicated to EPUB as well as technical information surrounding the standard:
- EPUB 3 community group is free and open to everyone.
- EPUB Accessibility 1.0 specification
- EPUB Accessibility Techniques
- Inclusive Publishing has EPUB guidance for all 4 of their user groups.
- User Stories and Samples
- Conformance and Validation