Judy Blume is a popular author of "young adult" novels. What sets her apart from the rest is that her novels often tackled topics like sex and masturbation. Not only did she write about teens having sex and wanking, she managed to do so without demonizing the characters who did so. The main character in Then Again, Maybe I Won't was even a peeping tom for quite a while, he even asked for binoculars for Christmas so he could more easily watch the girl across the street.
Her less controversial "Fudge" books were fairly popular, but I never did like them myself, mainly because the main character was so much younger than I was when I read them. I had the same problem with all of Beverly Cleary's "Ramona" books, I always wished they would have been about her older sister Beatrice instead.
Judy has also written a few books for adults, such as Summer Sisters, Wifey, and Smart Women. I haven't read any of those, since they seem to be aimed at more of a female audience. But one of them is rumored to have some lesbian scenes, so you may want to check them out, if that is your cup of tea.
Complete list of Judy Blume's Works