The following sites give some excellent information on rats and reproduction.
A *very* good article on all aspects of raising a litter of rats.
In case you run into trouble--here are links to two articles which discuss the care and feeding schedules of orphaned baby rats.
This site shows a normal, healthy (though somewhat graphic) rat delivery.
The following link takes you through the developmental stages of baby
rats--hair growth, hearing and vision (good pictures).
This link contains good advice for feeding the ratlings after the intensive first 4 weeks. <http://hometown.aol.com/RistoRat/nutrition.html>
Sarah Shuman's article on socialization of baby rats will help those babies become friendly and confident. <http://hometown.aol.com/RistoRat/social.html>
And last of all, how to tell those baby boys from the girls.