Gifs in iBooks Author

Pngs or jpgs... I use .png

gifs require being included in HTML, such as in a Widget, otherwise.

So if I put an animated Gif in an HTML widget it would work?

No, then iBooks Author will not import the widget. However, you can create a widget contining the URL of the GIF you want displayed. This widget will both import and display.

If you need animation, consider using a media widget/movie instead...

reguar gifs are fine, the animated ones don't seem to work though.

(pdfs also work, not sure about when publishing through itunes)

from the IBA help: