The following resources will help you create your ePUB files.
The International Digital Publishing Forum (IDPF) develops and maintains the EPUB® standard format for reflowable digital books and other digital publications that are interoperable between disparate reading devices and applications. It is responsible for the ePUB specification. The IDPF approved the ePUB 3 specification in September 2011.
The IDPF now hosts the ePUB Validator for ePUB 2.0(1) and ePUB3 based on the EpubCheck. It allows you to validate your ePUB file online.
You can also download EpubCheck locally and run it from your command line or terminal, which you will need to do for any ePUBs over 10MB or large batches of ePUBs.
eBook Architects has a list of resources for creating ePUBs and other eBook formats.
InDesign to ePUB Resources
Anne-Marie Concepcion has a series of videos on creating ePUB files from InDesign on Lynda.com.
InDesign CS5.5 to ePUB, Kindle, and iPad DVD-ROM is also available from lynda.com.
In this video from MAX 2011, Colin Fleming gives step-by-step instructions on how to take your content from creation to publication to distribution on the Sony Reader, Kindle, and iPad. It is the fourth video down on the page.
Elizabeth Castro’s ePUB: Straight to the Point is an invaluable resource form converting books from InDesign to ePUB. Liz has also written three Miniguides to go along with the book: Fixed Layout ePUBs for iPad and iPhone; Audio and Video in ePUB; and Read Aloud ePUB for iBooks. I recommend buying the ePUB of this book even if you prefer to read a print edition since the ePUB is DRM free and you can open it to see Liz’s actual coding.
ePUB Creation Tools
Calibre is a free and open source e-book library management application developed by users of e-books for users of e-books. It has a cornucopia of features divided into the following main categories: Library Management; E-book conversion; Syncing to e-book reader devices; Downloading news from the web and converting it into e-book form; Comprehensive e-book viewer; Content server for online access to your book collection.
Sigil is a multi-platform WYSIWYG ebook editor. It is designed to edit books in ePub format.
Vook is in the process of transforming itself from a maker of enhance eBooks with video embedded in them to an ePUB creation platform. Currently in beta.
PressBooks is a new book publishing platform, built on WordPress, that will make it easy to collaborate with an editorial team, and to generate clean, well-formatted books in multiple outputs: .epub, print-ready PDF, InDesign-ready XML, and of course HTML. PressBooks is brought to you by the people behind Book Oven. Currently in alpha.
CircularFLO is a new software product that converts Adobe InDesign books to fixed layout EPUBs suitable for the Apple iBookstore in a single click.
The single most helpful post I have come across for adding links to indexes is this one from Liz Castro’s blog Pigs, Gourds, and Wikis. You need to know a little GREP/RegEx to adapt it, but it works like a charm to create a linked index.
This is a great overview of the HTML5 specification with examples of how tags should be applied.
XML Editors for ePUB