Light weight or bodyweight exercises are great for beginning, but heavier weights are needed for muscle to grow.
Compound exercises that target your glutes are going to give you the best results. (Examples -> )
Stick with the same routine for a period of time, and increase the difficulty as your body adapts (as in increasing weight or reps).
While this can vary, hypertrophy (muscle growth) happens when you lift a challenging weight for 3-5 sets of 8-12 reps.
Your muscles need fuel to grow! Get plenty of protein (about 1g per pound of body weight) as well as carbs for energy - and yes, fats too.