UU Our Whole Lives Lifespan Sexuality Education Curricula -- specific guides can be helpful too, such as The Girls' Guide to Growing Up.
This book takes girls through all the aspects of puberty: changing bodies, privacy, menstruation, masturbation, etc. It is also written with even more frankness than most puberty guides; I've never seen a photographic guide to understanding when it might be time to change a sanitary pad, for instance. And it reassures girls that while some people have crushes, others don't (since many autistic people are asexual, this casual reassurance during such a foundational time is important). It also tends to use "person" instead of "boy" when discussing sexual feelings, which reflects reality. The tone overall is very friendly and comforting.
It is written for a third grade reading level, with plenty of photographs and illustrations. This tone could be helpful for a girl who needs a more direct approach to understanding what the heck is happening to her feelings and her body (as I will admit I could have used), or a girl with developmental or intellectual disability. But I've also been told that the tone feels too young for girls who are used to reading at a teen level, which is something to consider if you are buying the book for someone else.
If you know of other puberty and sexuality resources that are appropriate for our community, or if you have an opinion on The Girls' Guide to Growing Up, please do leave a comment. -SR