Sex Education

Hi, I’m not a parent but I think you all will have valuable information on this topic and I really need advice. I grew up with little to no sex education and have a brother that is 13. It seems my parents are going the same route of minimal sex education other than the basic, Christian and science aspect of it. Basically, this is what a penis and vagina is and nothing else. I want to help him grow and be better than I was and I want to be able to have him learn properly where I had to learn things by myself. Does anyone have any books or resources that I can give to him? I want something my Christian parents will be somewhat approving of but also something that has proper and healthy education for him to learn properly. Any advice would be appreciated.