For Unit 2, I found a book called: As the Crow Flies by Gail Hartman. It was useful in introducing maps.
I also played a game with my second grade students called the Four Directions Game. I labeled the room with N, S, E, and W and had someone count to 10 in a corner of my room while children chose one directional sign to stand under. The person doing the counting called out a direction and if children were standing underneath that sign, they had to sit down. The winner is the person left at the end of the game. It's very similar to 4 corners.