Hi Chuck,
Make sure your Outlook format is set to HTML. Open the animated .gif using
Internet Explorer. Right click on the .gif and copy it, then paste it into
your signature (Tools > Options > Mail Format > Signature Picker > Edit -
this will edit your current signature and you can paste the .gif to that
location). There are other methods to do this of course, but this is very
simple and straightforward.
If you have any issues or further questions, please post back.