• Scholastic Dictionary Of Idioms by Marvin Terban
• There’s a Frog in My Throat: 440 Animal Sayings a Little Bird Told Me by Loreen Leedy and Pat Streets

I had the students choose 4 idioms after looking through the books.  They made a poster of each one writing the idiom, its meaning, a sentence with the idiom used properly, and then an illustration of the literal meaning of the idiom.

This went over well!   The kids did a great job on their posters!