Here is a set of labels for classroom libraries. It is a set of 10 editable labels for bins or shelves. Sorting books by lexile level in the classroom helps students to find a book that is in their independent reading level and helps to keep the classroom library organized. These labels can be affixed to the shelf or to buckets to sort the books.
In my classroom, the books in the classroom library are kept in buckets I purchased from the dollar store. On each bucket is a label with the lexile level. At the beginning of the year, the students take a reading assessment to determine their lexile level (the test is also given at the end of each quarter to update their levels). All of the books in the classroom have a lexile level marked on them. The students know to put the books in the bucket that corresponds with the number on the back. It also helps students to find books within their comfort range for independent reading.