These are colorful library cards for your personal classroom library. It's so much fun to check out books with your very own library card! My 1st graders loved these this year. Every time my kids went to check out books they would go get their library card.
You can use the colors to form your reading groups. For example: Everyone with a yellow library card reads with me on Mondays and Wednesdays.
You can keep track of each students' reading level by putting a sticker dot of their level on each of their cards. You can make the level however you label your classroom books, which is what I did. The kids also know what book bin they can pick out of during independent reading time.