I can only recomment GIF-Paradies.de. You can choose between thousands of gifs there to make your webpage look... I don't know.... fancier. Although the page is on german, you'll find out where to find what soon.
For girly pages there's another great gif-page: glitter-graphics
Actually this works like adding sparkling text. First you choose a gif from *here*. I'm going to put up some instruction for learning how to put up gifs from other webpages and so on soon, but first let's do this.
If you found a gif you like (I chose a firework in this example) click it and copy the first URL into the < > Widget/HTML window.
Deleting the link or replacing it just works as in "Text & special Headings" explained.
Here's my gif, which is leading to "Home" on my webpage by clicking: