I'm no expert, but if I were stuck with dumbbells as my only strength and power training equipment, the following exercises would be my first choices:
- Lunges with maximal weight
- Power cleans, and power snatches with heavy but submaximal weight
- Overhead Presses and Push Presses with maximal weight (NB: these combine well with the power cleans)
- Turkish get-ups with submaximal weight, for stability in the shoulder girdle and trunk rather than maximal strength
- One-arm rows
- Farmer's walks
- Squats or goblet squats
- Swings, as with a kettlebell, for conditioning and posterior chain development
With maximal weights, sets of 5 are good. With sub-maximal weights, sets of 8 or more are better for most purposes. I'd shoot for "heavier" rather than "more reps" as a general rule, particularly since you'll eventually run out of heavy enough dumbbells.
I might do something roughly like this:
- A: warm-up, 3 sets of 10 weighted lunges, 3 sets of 3 snatches, 3 sets of 5 clean-and-press (power cleaning the dumbbell once for each press), two sets of one-arm rows on each side, heavy farmer's walks
- B: warm-up, five Turkish get-ups each side with moderate weight, 3 sets of 20 squats, 3 sets of 5 hang cleans, 3 sets of 10 push presses (power cleaning once for each set), a set of 20 swings
Make sure you use the full range of motion in each exercise, keep your back straight for everything, learn good form, and lift heavy. If you need more conditioning work, run, using both sprints and distances up to 5k. I'd do some bodyweight work (read: dips and pull-ups) to round out the training.