Hi!
Annimations are simple depending on how you want to make them. You can use microsoft gif animator, a download online. It's a simple click and place procedure.
But first, you'll need gif's for it. By taking a screenshot or ripping the pic of your avi, you can then edit it bit by bit using paint or photoshop (I prefer photoshop) Having a graphics tablet makes it easier, but I always do mine with mouse (my pen broke XD )
Always remember to save each frame you create as a separate file (always as a gif and always the same measurements)
I feel like I'm forgetting something..but I'll check back in case I remember XD