The Basics...
Embryology is the study of the development of the human baby during gestation. The human gestation time is 40 weeks, measured from the first day of the last menstrual cycle (38 weeks from conception). During this time, the embryo develops from one cell to the trillions of cells that make up all your organ systems. This is a tremendous accomplishment in such a short time frame!
External Links...
Gender Testing
Epidural Tutorial
Fetal Development Pictures
Fetal Develpment By Week
Visible Embryo
Rhesus Factor Problem