Here's a basic Dumbbell workout routine that can be used by golfers to help improve strength and power. Strength and power are both important physical characteristics for golfers. Not only for helping increase club head speed, but also reducing risks of injuries.
Many of the workout variables, such as sets and reps, will depend on your current level of fitness, age, goals, etc, but here is a really simple progression scheme. Using progressive overload is important, so you will need to increase the weight of the dumbbells as you go... below is a 6 week example.
Week 1-2: 2sets of 12-15 reps, focus on slow eccentric (2-3 seconds)
Week 3-4: 3sets of 10-12 reps, 2s eccentric and 1-2s concentric
Week 5-6: 4sets of 8-10 reps, explosive with concentric portion
NB: the DB Snatch and Squat jumps should be performed explosively throughout the six weeks.
If you are training at home and cannot increase the load/weight of the dumbbells, you can increase the number of reps, or slow the tempo of the exercises down or perform more sets to make things more challenging. However, you will be moving away from training strength and power, and most likely training strength-endurance. This isn't always a bad thing, but really depends on the goals of the training programme.