Flash is extremely popular as it allows for animated images of relatively small sizes and has the added benefit of allowing actions. Many spectacular navigation bars are the result of flash authoring.
The following sites are a variety of Flash MX 2004 help/tutorial sites or manuals and various more modern sites which use newer versions of the software. That being said, many of the ideas can be created on the older version. Use the help button or Google to seek out ways to accomplish what you want.
Google Drive Folder
with files required for Tutorials below
NOTE: If you cannot see the tutorials below, you'll need to be logged in to your Google Cloud account!
Adding an object, converting it to a symbol, adding an action
Adding a layer, another use for a motion tween
Adding one more way to do a motion tween
Adding Sound - Part 1
Adding (Mixing) Sound - Part II