The three main exercises during the resistance program are squats, leg press and leg curls. Leg press and leg curls are usually on machines that are fairly simple and straight forward to use.
The squats can be more of a challenge and really important that you use good form. We do recommend getting with technique from a trainer. You could also watch a YouTube video on proper squat technique then record yourself doing it to make sure you are using proper form early on while the weight is light.
Perform the three lifts in this order: 1) squat, 2) leg press, and 3) hamstring curl. During each lift, keep the range of motion specific to cycling . Never bend your knees more than you would on the bike . That usually is 100 degrees for all pedal strokes. When you perform the squat, lower the weight down until your knees are bent 100 degrees (just above a right angle) and then perform the upward motion of the lift. (Many research groups have looked into the effects of different “squat depths”, FasCat recommends using a conservative and safe depth and staying away from extreme versions of the squat.) Follow the same approach for the leg press—lower the weight down to 100 degrees and back up. For the leg curl, bring the weight completely up to your back and gluteus muscles.
Here is more information on it: