Posture -

www.wholewoman.com has wonderful information regarding the importance of posture and how to maintain proper posture.

Treat Your Own Back by Robin McKenzie has very good information on proper posture and exercises to help train yourself in maintaining your natural lumbar curve.
 

Surgery -

The American Urogynecological Society website has good information about surgery and what to expect.

Childbirth -

The Hypnobirthing book and forum provide good information on proper pushing technique, as well as how to relax during labor, which protects your body.