Synchronising Your Sound
Next you have to select what kind of synchronisation you want. Event syncs the sound to, you guessed it, an event. It will play from it's starting keyframe to the end, totally independent of the timeline even if the movie stops.

Start is similar however if a sound is playing and a new instance of that sound is started the old one will stop. The Stop option will stop a sound.

Stream will sync the sound to the animation. Ideal for websites. If Flash fails to draw a frame in time it will skip that frame in order to keep up with the sound. Stream sounds will stop when the movie stops and can not play longer that the frames it has been placed in.

Advanced: To stop all the sounds from playing use the action Stop All Sounds.

Next you need to enter a Loop value to specify how many times to want the sound to loop. For continuous play enter a very high number. I tend to use 999.

Have a play with the Sound Options. They are pretty self explanatory.

You have just added you first sound!! Now begins the long process of developing an ear for what sounds go well with what sounds. Enjoy!