Which exercises to tone butt and thigh muscles?

I was wondering of any exercises I could do to build the musicles in my thighs and bum. im pretty happy with them, but I would like a little more curve in them.

I heard squats are quite good, I have been doing them for a few days... if this is a good exercise how long do you suggest I do these per day. I have a fairly balanced diet and always eat until I feel full.

Lunges are probably the best exercise to hit your quads and glutes. I notice that the women at my gym who have nice bottoms and legs do a lot of lunges.