In this tutorial we are going to learn about animation, and using those animations to create animated gif files that can be placed on your website. To start off, we need something to practice our animations with. Lets create a ball! Use your ellipse tool to draw a circle.

Change the fill mode to gradient, and the gradient mode to radial. You can use any colors you want, I changed mine to yellow / orange, making sure that the lighter of the two colors starts in the center to create a rounded effect.

Next I added a dropshadow to my ball by clicking on the + menu in my properties tab, and choosing Drop Shadow.

Now that we have our ball, we need to change it from its nameless vector form into a symbol. To do this, right click on your ball and choose Converter To Symbol.

We may be creating an animation, but don't let that fool you! Give your symbol a name, and choose "graphic" not "animation."

Now we are going to create focal points of your animation, and use firework's tweening abilities to fill in the gaps. Duplicate your ball by copying it (Ctrl+C) and pasting it (Ctrl+V). Place your copied ball to a place that you would like it to move to in your animation.

Copy it a few more times, and place them in an order that will create a nice animation. For example, I want my ball to bounce. My first frame will will be at the bottom, then it will move upwards, then downwards once more, and then bounce off the screen. You can dictate the direction of your ball as you see fit.

Now that we have our animation mapped out, we are going to tween these symbols. Hold shift, and click on all of your copied calls. Next choose Modify > Symbol > Tween Instances.

Choose the amount of frames you want, this will decide how large your file is and how smooth the animation. The more frames the larger the file, but the smoother and more pleasing the image. Click on the "Distribute to Frames" box.

You will see that your copied symbols have disapeared. If you open your frames window, you will see that frames have been added. Towards the bottom of your screen you can preivew your animation be clicking on the play icon.

Next we are going to save our animation as am animated gif, Choose File > Save As. make sure to click on the Save as type dropdown menu, and choose Animated GIF (*.gif).

Save your file, and your done! Here is how mine turned out.