I really liked adding sounds. I thought that it was one of the easier things in flash that I have done in a while, but in the beginning I didn't know what to do. I solved this by watching the video on the wiki that it had for adding sounds. I have always liked the videos that they give to show what to do, but this one helped more than usual. I felt like it gave more of a step by step than all the others.
Adding sounds helped me a lot with the layers on the button itself and I know that I will need to know that info for my game. I dont know how I will use sound in my game.