In schools and libraries where Halloween celebrations are permitted, it can sometimes be a challenge to find books to share that aren't too scary for the under-five crowd. Here are a few tried and true favorites that capture the spirit of Halloween without troubling kids' sleep.
This is NOT a Pumpkin
by Bob Staake
It sure looks like a pumpkin from every angle, but at Halloween, this orange gourd becomes something even more exciting. (Hint: It has a face, and it lights up at night!) I have only used the board book version with small groups, but it also makes a quick and easy flannel board to use with larger crowds.by Bob Staake
by Linda D. Williams
A pair of shoes, a shirt, and other creepy clothing articles follow the little old lady home one night, but she's not afraid of them - in fact, she has a job for them to do! This book is especially fun to act out with preschoolers and early elementary schoolers.
by Richard McGilvray
There are all kinds of silly creatures out tonight - best to stay in your cozy bed! (This book could potentially scare a very small child, but the reader's tone really determines whether it's silly or scary. I have used it with toddlers with great success.)
by Steven Kroll
Two mice fall in love with the same pumpkin but neither one realizes the other's plan to carve it and enter into the Biggest Pumpkin contest. This is one of the first books I remember buying at the school book fair when I was in elementary school, and it was a great alternative to the ghost stories my classmates were reading. 
by Ed Emberley
What better way to confront Halloween monsters than to banish them with the power of our imaginations? This book builds up a monster, then sends him away one scary feature at a time. This is a great one for large crowds who can repeat each line after the storyteller. 
by Wendell Minor
Where can you see pumpkin heads on Halloween? Almost everywhere! The illustrations in this book are beautiful, and the text is spare enough to make this a good title to share at multi-age story times, or sessions with lots of toddlers and babies in attendance. 
by Janet Morgan Stoeke
Minerva Louise explores the farmyard's Halloween decorations, coming to all the wrong conclusions. This is a great one for preschool story time - and even better if the audience is already familiar with the Minerva Louise "schtick."
Halloween Faces
by Nancy Davis
On Halloween, everyone puts on a different face. This toddler-friendly lift the flap book shows the fun of wearing costumes and might even help explain that the scary creatures wandering the neighborhood are just big kids dressed up. by Nancy Davis
by Anne Rockwell
Celebrate all the fun of Fall, ending with the carving of a jack o'lantern in time for Halloween. This works well in a seasons-themed or Fall-themed story time as well as a Halloween story time. It's perfect for twos and threes.
by Peter McCarty
Jeremy draws a monster who isn't scary, just rude! Thankfully, Jeremy knows when to say enough is enough, and before too long, he sends that monster packing. This book actually makes no reference to Halloween, making it a good alternative for schools and libraries where Halloween isn't celebrated. Check out my flannel board adaptation of this book here.