The calf muscles are one of the largest endurance muscles in your body. Trying to get your calve muscles to grow is almost the equivalent of trying to get the muscles in your jaw to grow. Think about it. Your calves are designed to be able to carry you for hours if you needed to walk a far distance.
Calves respond best to high reps and low reps. They are a mix of type 1, 2a and 2b muscle fibres. I recommend hitting them every other day or twice per week and alternating heavy days (6-10 rep ranges for working sets) and volume days (10-100 rep ranges for working sets).
Remember to do some seated calf exercises in addition to straight leg calf exercises to ensure you hit both the gastronomeus and soleus muscles.
I would say the two best exercises for calves are standing calf raises and seated calf raises.