30 Things Every Woman Should Have and Should Know by the Time She's 30 by Pamela Redmond Satran and the Editors of Glamour

A list of 15 must-haves (for example, a cordless drill) and 15 must-knows (for example, how to fall in love without losing yourself) for women age 30 and beyond, and maybe before.

It's an interesting list and easy to read. I don't think it's a book you need to own, so just check it out from the library when you have the chance.