I'm a big fan of Mo Willems, Sesame Street writer, author/illustrator, ....more MO. Love Knuffle Bunny. I was even more excited to see Knuffle Bunny Too on the bookstore shelf than my 4-year-old. And What could be more clear to a toddler then Time to Pee or Time to say Please?
If you're not familiar with his work visit mowillems.com. He has a dvd out with 6 stories. OK I'm not a big advocate of watching TV media for young children, but I do let my kids watch dvds like Clifford, Little Bear, Angelina Ballerina, Kipper, and Reading Rainbow. My kids make the text to TV connection, and I know the characters and story lines are appropriate for young children.