Teacher Requests - Book Lists

Some of you read my post about The Best Email I Ever Sent.  I took the responses and made them into a giant To-Do list.  It feels really great to have projects that are eagerly awaited for by my teachers!

So last week I created two book lists using GoodReads.  The first was a list of books about art and the second was a list of books about music.  They aren't comprehensive lists of all the titles I have in my collection.  I chose titles that I think have been overlooked or titles that are fiction and have an art/music connection.  The real purpose of these lists is to have a place to list new books as they come in to my library.

So far my art and music teachers have been very thankful.  Next up is a list requested by a fourth grade teacher for grade-level reads.  This is such a difficult topic to address.  By reading level?  By age appropriate-ness?  How do you handle requests for books by grade level?