Update: Apple’s decision to restrict material created with the iBooks Author platform from being sold anywhere other than through the iBookstore has started to create a bit of controversy. One author has likened Apple’s policies to “Adobe declaring that if you use Photoshop to export a JPEG, you can’t freely sell it to Getty”. Get the full story here.

With Apple just finishing up its biggest education announcement in recent years to introduce the new “iBooks 2.0” app and “iBooks Author” e-book creation platform, there are inevitably more than a few questions regarding publishing and distribution for authors and publishers. Fortunately, Apple clarified the intricacies of the new services in a support document.

A couple things we learned: Books created in iBook Author have to be distributed through the iBookstore if they are for sale, but free books can be distributed through the author or publisher’s own website if they choose. Books can be exported from iBooks Author for distribution elsewhere-in PDF, text, or iBooks document formats. All paid iBooks Author books require a sample, while free books do not need to have a sample. It also appears all books including textbooks will continue to have a 2GB file size limit, though some of Apple’s partners have textbooks as high as 3GB in the iBookstore.

Teachers and educational institutions will be happy to learn that Apple is allowing course material that users have created with iBooks Author to be used as part of tuition-based courses outside of the iBookstore. Not surprisingly, it does not extend to subscription-based services that are not considered “tuition-based” educational programs. As for iTunes U, publishers must already have an iTunes U website or sign up for one here before distributing their books through the new “iTunes U” app.

Apple also clarified that books will be published directly through iTunes Connect:

You can sign up to publish your books directly using iTunes Connect. To sign up to sell your books on the iBookstore, complete the application and download iTunes Producer. Books can also be made available for free on the iBookstore.

Apple will continuing taking its usual 30 percent cut and publishers will be able to set their own prices, but textbooks prices must be set under $14.99, according to Engadget. Apple also published several other documents today detailing best practices and tips for developers using the new iBook Author platform…

In one support document that outlines “best practices for using 3D models,” Apple noted the first-generation iPad could handle 3D objects with less than “20,000 moderately textured polygons,” while the iPad 2 can support 3D objects with up to “50,000 moderately textured polygons.”  Apple warned, “More complicated objects may result in an increased load time, slower behavior, or a blurry image” and suggested tips for lighting, textures, camera, exporting and previewing.

In another document, we learned that iBooks Author would indeed have an Accessibility Description function in the Widget inspector allowing developers to add descriptions of objects and images for Voice-Over users. Apple outlined the best practices for doing so here. Other iBooks Author support documents published today cover using “iPad-safe fonts when authoring books” and the best methods of adding “video to your iBooks.”

There still seems to be confusion over whether an “.iBooks” file is simply an ePub 3.0 file, we will update this post as we learn more. TechCrunch said Apple confirmed iBook files borrow from the ePub format (probably 3.0) and “certain interactive elements of the books require the files to be done in the slightly different iBooks format.”

Check out our full coverage of Apple’s education event and additional assets:

ARTICLE – Liveblog: Apple’s education-focuse media event in NYC
ARTICLE – Update on business metrics from Apple’s education event
ARTICLE – Apple releases iBooks 2, a brand new textbook experience for iPad
ARTICLE – Apple to price new iBook textbooks at $14.99 or less
ARTICLE – Apple announces iBooks Author, free Mac app for authoring textbooks
ARTICLE – Apple launches iTunes U, free iOS app for educators to take courses anywhere
ARTICLE – Apple releases iTunes 10.5.3 with support for textbook syncing to iPad
ARTICLEHeartwarming clip of teachers and students Apple played at the presser
ARTICLEAn overview of publishing and distribution for iBooks Author
VIDEO – Gallery of elements that can be used for interactive iBooks
VIDEOThe iBooks Textbooks promo
PR – Apple reinvents textbooks with iBooks 2 for iPad
PR – Apple unveils all-new iTunes U app for iPad, iPhone & iPod touch
SUPPORT – iBooks Author: Best practices for using 3D models
SUPPORT – iBooks Author: Use iPad-safe fonts when authoring books
SUPPORT – iBooks Author – How to make your iBooks accessible
SUPPORT – iBooks Author – Add video to your iBooks
SUPPORT – iBooks Author – Publishing and distribution FAQ
CHANGELOGiTunes 10.5.3 for Mac
CHANGELOG – iTunes 10.5.3 for Windows (64 bit)
APP STOREiBooks Textbooks section in iTunes
APP STOREiTunes U for iPhone, iPod touch and iPad
APP STOREiBooks 2 for iPhone, iPod touch and iPad
APP STOREiBooks Author for Mac