Here are some general guidelines for choosing an appropriate dumbbell weight:
Beginning male athletes: 12-20 lbs.
Beginning female athletes: 5-12 lbs.
Intermediate/Advanced male athletes: 25-40+ lbs.
Intermediate/Advanced female athletes: 15-25+ lbs.
Here's a sample circut that will work quads, hamstrings, glutes, hip flexors/extensors, deltoids, and triceps.
Try these exercises in order - do one rep of each lift for 5-8 total lifts in the set. Repeat the set 2-3 times.SQUAT