First put your animated gif inside your images folder for your web site. Make sure there are no spaces in the name!

Then in Claris HomePage, go Insert - Quicktime movie.

Double click on the movie once it is on the page, to get this window. Click the Auto-play option, and make sure you say no controller. You can loop it (meaning it plays forever) or run it back and forth, but the best thing is to leave it plain.

Now, when you use a browser, you will see the animation! Easy peasy!