BIG BUTTS!

I recently lost around 30 pounds & I'm at my goal weight. Now, I'd like to workout my legs/butt seeing as how when I lost weight I lost weight there as well. I never really worked out on my legs or butt and I just now realized I should have.
But I'm confused as to how to get a bigger butt with diet and exercise?
How many days do I workout my butt and legs a week? Do I eat more or eat as if I were dieting (small portions)? What exactly do I eat to help trying to get a nice bum? Please help! I'm really confused about all this.