We love mixing storytime with activities at my library, and one of my favorite themes is (obviously) art! There are really great books out there to sneakily teach aspiring artists some of the fundamentals of art while still holding their attention, and a lot of these books have some awesome activities we've used to really drive the lessons home.
One amazing series of books is the Dot, Sky Color, and Ish by Peter Reynolds. All of these books address different issues with art creation and getting over little speed bumps that trip us all up. The Dot has potential for a lot of really great activities, but really all you have to do is draw a circle on the page and let them go to town.
Another good set of books is Mix It Up and Press Here by Hervé Tullet. These books teach colors and color mixing in a fun and interactive way. When we did a painting activity later, one of the kids said "I know red and blue makes purple because of that book." Pretty good for a preschooler!
Art's Supplies by Chris Tougas is a humorous adventure into the world of Art and his talking art supplies. But on a deeper level, this book talks about and has examples of many of the basic art supplies we use on a regular basis.
A great book for teaching that accepting mistakes in art is sometimes a good thing, A Beautiful Oops by Barney Saltzberg is a book that is a must have for any child that is too focused on coloring inside of the lines. It's the perfect book to read when your child is upset because their art didn't turn out just the way they wanted.
Finally, we love the book I Ain't Gonna Paint No More! by Karen Beaumont. Not only does it teach the age old lesson of "you can't paint on the walls" in a fun way, it also has a great rhythm that makes it so much fun to read aloud. For this storytime we printed out a blank picture of the main character and had the kid's draw on him as we read the story.