An introduction to the anatomy of the vulva and vagina and what menstruation is all about, presented in a way that’s inclusive of transgender and nonbinary bodies. The authors, both sex-ed counselors and educators, intentionally do not use pronouns in the book. The information is conveyed through the dialogues of six characters, five of whom read as girls and one of whom reads as nonbinary or a trans boy. The book covers caring for your vulva and vagina, what the menstrual cycle is, and how to use a variety of menstrual products (though unfortunately it only shows an applicator-free tampon, not one with an applicator).
Simple, but an engaging place to start.