To view a longer list of Amazon products click Dumbbells
Dumbbell Workout is a very vague term because there are many, many different ways to do this. You can work all most all parts of your body with the dumbbell. There's the regular Bicep and Tricep routine, Shrugs, Concentration, Chainsaw, Bent Over Rows, Preacher Bench, etc.
Here is a site that shows twenty different Dumbbell Exercises with Diagrams.