None, besides the Godfather making me learn how to hide an awkward boner in 9th grade. Books are not the greatest choice anyways when it comes to learning about sex. It's very much an on the job training type of thing. But if you are thinking about having sex and are worried about looking like a complete and utter dunce, familiarize yourself with the all the bits through the internet. NOT PORN but diagrams of what's what and what's sensitive. Maybe an article on how to do something or what to be careful of. Then again partners can be significantly different and things that work for one couple may not work for you.

Honestly the best way to learn about sex is none of the above, but rather through open communication with your partner in the bedroom. It might be clumsy at first. that's ok. No one expects you to be Casanova your first time. Pay attention to how your partner responds to touches and listen when tell to do or not to do something and be open with what you will and won't do without feeling pressured to do something that makes you uncomfortable.

In a more personal note make sure it means something. Make sure they mean something. You are going to remember that moment with absolute clarity for probably the rest of your life so make it a good memory.

Ok friend sorry if that's more than you asked for. But I felt it needed saying. Have fun learning about the birds and the bees whatever your route.