This post is remarkable in that it covers pretty much everything you need to know about getting started with iBooks Author. In other words, Apple has created a tool so intuitive that you only need a blog post, not an entire book, to understand it. So here it is…
iBooks created in iBooks Author can only be read on an iPad. This might seem like a limitation at first, but the iPad has completely dominated tablet sales to date, especially in the design and building disciplines.
There was an uproar after the initial release of iBooks Author due to licensing language that made it appear that authors using iBooks Author were signing over intellectual property rights to their work to Apple. But Apple quickly came out with language in v1.1 that clarified the issue. The upshot is that if want to sell the book in .ibooks format, you have to do so through the iBookstore. But if you want to sell it in any other format, you can do that anyway you like. And yes, you always own all intellectual property rights.
Buying iBooks Author
Actually, you don't need to buy iBooks Author. It's free at the Mac App Store. Apple makes all their money when your iBook is sold in the iBookstore.
Buying an iPad
You really should buy an iPad with a Retina Display to test your book as you're working on it. Using a pre-Retina iPad may result in your images looking rough when your book is read on a new iPad.
Selecting a Template
Once you've downloaded and installed iBooks Author, your next step is to select a template for your book. Apple currently has only a handful of templates built into the app, but they are excellent. There are also third-party templates available, with more arriving constantly. Find the template closest to the look and feel you want, then modify it and File>Save As Template… so you can use it over and over. I modified Apple's Basic template for New Media for Designers + Builders.
You can only use the fonts that come pre-installed on iPads in iBooks. Fortunately, they have several really good ones, so this isn't the limitation it might appear to be. There's one trick: If you use the Fonts window by clicking the Fonts icon in the toolbar, it'll show you all the fonts currently available on your Mac, including fonts not available on the iPad. So don't do that. Instead, View>Show Format Bar and use the font pull-downs there, which will only show you the fonts available on an iPad.
One other caveat on fonts: As with other apps that use text styles, don't custom-format anything at all in your iBook. Instead, use styles for everything. This way, if you want to change the main body text or whatever, you only have to change it once and iBooks Author makes that change throughout the document. Saves tons of time.
Building the Book
Conventional wisdom has it that you should write your book in a word processing program, then flow the text into your publishing program (iBooks Author in this case) and drop in the graphics. I think this may be an idea left over from the old days when one person wrote the book and someone else laid it out. If you're doing the whole thing, then it makes much more sense to write the entire book in iBooks Author from the beginning.
I cross-link freely within a book so that people can surf the book just as easily as surfing the web. But before you can link to anything, you have to tell iBooks Author where you want those links to go. You do this by setting bookmarks where each link should land. You'll like bookmark a little, then link a little, then repeat… over and over again. To bookmark, select the text you want to bookmark, then with the Links Inspector open and the Bookmarks tab selected, click the + button in the bottom left corner of the Inspector and it'll create a new bookmark and name it the same as the text you've selected. You can change it, but I usually leave it because then you don't have to remember what the custom name is linking to.
The ability to link to things on the Web is one of the great strengths of e-books in general, so use this ability freely. New Media for Designers + Builders breaks new ground in this regard by using this companion site to host content that only some readers need, reserving the iBook for only those things everyone should read, as described here.
Currently, you can only use body text to anchor links. This means you can't set up a graphic to link (by clicking on it) to anything. I consider this to be an "upgrade waiting to happen," and can't imagine why Apple hasn't already done this, but this isn't a deal-killer.
To make a link, go to the Hyperlink tab of the Links Inspector and, with the anchor text selected, click the Enable as Hyperlink checkbox at the top of the Inspector. Once you do this, it opens up all the options. If you select Webpage, it'll open a box where you enter the URL of the page you want to link to. Links are by default active unless you check the Make All Hyperlinks Inactive box at the bottom of the inspector. If you select Email Message, it will open two boxes: one for the recipient's email address and another for the subject of the email. If you select Bookmark, it will open a pull-down listing all bookmarks in the document. Select the one you want to link to, obviously. Finally, if you select Figure, it will allow you to link to any named figure in the document. More on that later.
Objects include everything in your book except the main page text. Objects include graphics, text boxes, shapes, tables, charts, and widgets. Here are the subtypes of each of these object types:
Graphics can be set in the Wrap Inspector to either Inline (moves with text,) Floating, or Anchored (moves with anchor.) If set to either Floating or Anchored, then you can add a title and/or a caption. If you add a title, then you can select the title label (Diagram, Figure, Gallery, Illustration, Image, Interactive, Movie, or Review.) If you select Figure, then you can link to figures as noted in Links above.
I haven't yet found a use for text boxes. Between the main text window on each page, graphic titles and captions, I'm quite happy. Nonetheless, if you need them, you can create them.
You can create a number of shapes, including lines, circles, rectangles, and various polygons. You can then format them using the Graphics Inspector, the Metrics Inspector, and the Color window.
Tables & Charts
The tables and charts you can create in iBooks Author are similar to what you can make in other programs such as Pages.
iBooks Author has a cool collection of widgets. Galleries allow you to flip through a collection of interactive photos. The Media widget allow you to include videos and audio files. The Review widget allows you to create quizzes. The Keynote widget allows you to place entire Keynote presentations within your book. The Interactive Image widget is really cool; the best way to understand it is to download iBooks Author and play with it. I've never worked with anything quite like this before. The 3D widget allows you to place 3D objects such as those you might create in SketchUp into your book so people can turn and twist them with just a fingertip. Finally, the HTML widget allows you to insert Dashboard widgets or other HTML widgets created with Apple's Dashcode into your book.
There's more, of course. iBooks Author automatically creates cool tables of contents, and also really useful glossaries. But while there's a growing collection of third-party manuals, there's a pretty good chance that you can figure it all out based just on this post and a bit of experimentation. Give it a try!