While exploring search engines for kids today I found a great site for teachers and parents that are trying to teach kids about sex. The webpage is designed for tweens or early teens who are just hitting puberty. It is informative, not intimidating and does not have any nude photos. The site encourages kids to wait but makes sure they know about protection and risks should they choose to have sex.
If this sounds like something you or your patrons need check out The Hormone Factory.