Great drawing

As for your question; I personally use GIFAnimator to animate my stuff, and it's not a trial program and it is quite nice, you can specify how long you want each frame to be and if you want it to loop and so on. I forget where I downloaded it though, so if you want it I'll have to email it to you.

To make an image transparent it must be a GIF for starters (which is alright in this case since animated images must be GIFs anyways). You can make your image transperent in PhotoShop. Just click the little magic wand tool to make it simple and click the white area, then delete it all and you will see little b&w boxes under it, then you just click save for web and save it as a transparent GIF and then you put the frames together in GIFAnimator.

Hope that helped some Let me know if you want me to email the program to you and what your email address is! It's not a very big program, so don't worry.