My favorite when I was very small was "What Do People Do All Day?" by Richard Scarry. It's well written and illustrated, and explains what different occupations are, etc. My copy fell apart, I read it so much.
The only problem I have with it now, as an adult, is that all the adult female characters are stay-at-home moms. I don't think any of them had careers outside the home. The book did address the challenges of being a SAHM, though.
Are You There God, It's Me Margaret is banned?? Heh, even my ultra-religious parents let me read that. Then again, I grew up in a school district where The Catcher in the Rye was on the required reading list.