This is a great non-profit organization. I've given my nieces and nephews copies of their Pre-Natal Care DVD it is so full of good information, especially great for the new parents who want to know everything that's going on with each phase of their baby's development. The website itself however is so full of general healthcare and prenatal care information that you'll use it as a go-to for lots of health issues in your life.
This is a great site for teachers involved with human development, sexuality. It also provided week-to-week fetal development for expectant parents to track their baby's growth. It's free!