What’s Happening to Me? Boys’ Edition by Alex Firth, Susan Meredith, illustrated by Adam Larkum (ages 10 and up)
Well written, approachable, covers many of the most common (and hard-to-ask) questions, BUT heavily communicates heterosexuality as the norm, only VERY briefly mentioning the possibility of same-sex attraction. The illustrations suggest it’s for very young kids, but the content is fairly comprehensive, including sex/sexuality.