I did a Flash Animation course a little while back and I was absolutely suprised at how easy Flash is to learn. If you're aren't interested in learning it via a course then I definately recommend using the built-in tutorial that comes with Flash, I took a look at it after completing the course and have to say that Macromedia have developed an extremely user-friendly tutorial for beginners.
You could also try
www.learnthat.com, they usually have good free tutorials/lessons regarding multimedia programs and certifications.
Have fun!