Todays Parent.com is a Canadian Publication that covers virtually everything you can think of as an expectant or new mother.
Pregnancy.about.com is a great source that helps mom understand what's happening to her body both with child and after birth.
Pregnancy.org not only offers typical articles about child rearing but also has a huge community with forum support for nearly 90,000 registered members.
Pregnancy without Pounds is a site run by a health and nutritionist coach that aids the mom to be to nurture a perfectly healthy baby while not setting off the Richter scale.