T.F.
When my daughter was young (she is 14 now) I bought a series of books by Joy Berry called "Help Me Be Good". Each small book was directed at a specific behavior....example...whining, teasing, lying, complaining, interrupting, etc..
They had great examples geared toward the youngster that understands what is going on...EASY to read and discuss.
My daughter loved the books.
I know they are sold in Bookstores and on Amazon but I have also seen them in the local library.
Good luck.