Tree of Sex
http://www.nature.com/articles/sdata201415
This is an open-access database providing information about mechanisms of sex determination.

Copulation by the European adder (Vipera berus)
http://www.arkive.org/adder/vipera-berus/video-09b.html
The left hemipenis of the male is inserted into the female’s cloaca.

Sex organs of male turtles
http://blogs.scientificamerican.com/tetrapod-zoology/terrifying-sex-organs-of-male-turtles/

Mating, egg laying, and hatching of Blanding’s turtles (Emydoidea blandingii)
https://www.youtube.com/watch?v=RnqHUkxaqQE

Courtship and birth of the shingleback skink (Tiliqua rugosa)
https://www.youtube.com/watch?v=aPZiAiUYS8o

An American alligator opens her nest and transports a hatchling to the water
http://www.arkive.org/american-alligator/alligator-mississippiensis/video-09a.html

Embryonic development. These videos show chickens; the development of non-avian reptiles is very similar.

• Time-lapse photographic sequence
  https://www.youtube.com/watch?v=-Ah-gT0hTto
• Animation of development
  https://www.youtube.com/watch?v=PedajVADLGw