I am a consultant that has published media in offset print, Book and ebook Publishing, iPad iBook, Kindle, Nook other epub formats. I recommend using Microsoft Word or iBooks Author tool as a good start. Then the file can be slightly modified and formatted for the other tablet readers. People with more complex needs including printing will also need to use Adobe InDesign and other programs too.
I am probably one of the best people you could ask for help with your book publishing project. I used to be in the pre-print part of the publishing business. I would create four color film separations for printing, using one of the first Postscript Linotronic laser typesetting machines in Northern California. The 3 foot wide film would be processed in an Oscar-Fisher film processor (in a dark room), and would be used to create the metal plates used in the offset printing process. As President of Pinnacle Type, I would find projects, write, edit, do book layout, or hire people to do these jobs, and publish books and magazines.
Many books came out of those times. Information Moscow by Jocelyn Stoller and Anya Khucharov. Butterfly by Norrie Huddle. Mondo 2000 by RU Sirius. The pre-press film business has disappeared, and now everything is digital and direct-to-plate. PDF format and on-demand publishing, and an over-seas printer to offset print a short-run of bound books, is how many people handle their book. There are so many authors I have talked to that are glad they self-publish. They used to only get an advance on their book. Now they get all the sales of their own books. A recent book I edited is Earth 2012: Time of the Awakening Soul by Aurora Juliana Ariel, PhD. I was also the panel moderator for a 2012 and Ascension Discussion Panel at the New Living Expo in San Francisco, and I have been part of the 2012 Ascension Panel team at the Conscious Life Expo in Los Angeles.
As Vice President of R & D of Digital Resource Corporation, I also developed interactive CD-ROMs and touch-screen kiosks. I even created a rear-projected image kiosk that looked like a screen-less hologram. This was for Digital Media Associates and installed at Island Swimwear in Maui, and the image was a bikini-clad model spinning a a turn-table. I also created music kiosks for Walden Books and Disney World. Then I produced audio CDs and video DVDs, and now all sorts of media downloads.
Ebooks and PDF files have been around for a while. Now they can be formatted for the new electronic readers and converted into the new standard, which is epub files. Then your book can be downloaded from the iBook Store and synced to an iPad. Alternate readers like Kindle, Nook and others can also have versions of your epub book.
Video Book Publishing and Article Book and Magazine References:
TWIMC by Michael Tobias and Chris Traub (Editing and layout by Edward Ellsworth)
The Ladybugs by Zoe Sexton (Editing and layout by Edward Ellsworth)
Information Moscow by Jocelyn Stoller and Anya Khucharev (Editing and layout by Edward Ellsworth)
Butterfly by Norrie Huddle (Editing and layout by Edward Ellsworth)
Mondo 2000 by RU Sirius
Earth 2012: Time of the Awakening Soul by Aurora Juliana Ariel, PhD (Editing and layout by Edward Ellsworth)
The Maui Magical Mystical Tour by Kathy McCartney (Editing and layout by Edward Ellsworth)