there are a ton of different workouts that you can do with dumbell exercises. they are the most versitile piece of equipment that you can use to build mass and get stronger. you will find that you can really create alot of workout  intensity with them.  this is one of their major advatages. you will have a hrder time doing this with a barbell or a machine. when you are using dumbells you can bring up unbalanced muscle groups too.  you ca train unilateraly and hit that side of your body as hard as you want to. this works great.