Breathing and death are considered two undeniably realities of life. I would say that sex is right behind those two.
[Edited for length - MODERATOR]
Ways to Prevent Yourself from Getting Pregnant
Preventing Pregnancy after Sex
How to go about Unplanned Pregnancies
Abortion/Termination of Pregnancy, how to go about it, implications and risks
Sexually Transmitted Diseases (STI)
How do I know I have an STI?
Types of Sexually Transmitted Diseases
Reasons you Might Contact a Sexually Transmitted Infection
How Can I Protect Myself From STDs?
What to do if you Think you have a STD
Libido, factors that may be Affecting your Libido or your Partner's and how to Improve it
Orgasm
Things that have been stopping you from having an orgasm, How to achieve one, how to achieve Multiple Orgasms and things you need to know about Faking an Orgasm
Testimonials and life experiences from living people based on there sex experiences.
And many more.
you can get it on Amazon for $3.49
http://www.amazon.com/dp/B00LU6N84S