New to sprite sheets / animation

Hey everyone. I have a website for kids games called RoomRecess.com and am wanting to extend the site to include some games that have some minor animation. I have a sprite sheet with a character’s walking sequence on it (facing 4 different directions) and am wanting to learn how to best use that sprite sheet effectively. I have been unable to find a simple tutoral to do this with Action Script 3. Could anyone please offer some advice? Thanks!