A.J. and his friends get a Personal Digital Assistant named Miss Porter as a substitute teacher, who can order pizza and tell endless jokes, but grows power-hungry when her system is changed and tries to take over Ella Mentary School.

In a series of letters a student laments the absence of her teacher and daily routine, but she soon realizes there are benefits to mixing things up, and that perhaps having a substitue teacher is not so bad after all.

After Susan sees Mr. Smith the substitute teacher peel off his face, she knows he's an alien and only Peter believes her. Together they work to save the class from Mr. Smith's horrible plans.

"Cat is not so keen on stepping in as substitute teacher at Kitty School, but he's surprised by how much he's able to teach the kittens--and how much he learns from them"--

Mr. Creacher, a multi-tentacled substitute teacher, warns his prankish students not to misbehave, recounting rhyming cautionary tales of the weird, spooky, and unexpected.

Before you enter Wayside School, you should know that it's a thirty-story building with one classroom on each floor. Mrs. Jewls teaches the class on the thirtieth story. Miss Zarves teaches the class on the nineteenth story--except there is no nineteenth story, so there is no Miss Zarves. Understand? Good. Explain it to Calvin. More than fifteen million readers have laughed at the clever and hilarious stories of Wayside School. So what are you waiting...

Dive into four new stories about Narwhal and Jelly becoming substitute teachers! The two best friends come across an enthusiastic school of fish one morning. Unfortunately, Mr. Blowfish, their teacher, has come down with a cold, and class will have to be cancelled ... until Professor Knowell (Narwhal) and Super Teacher (Jelly) volunteer to help out! The first subject is Wafflematics, in which Narwhal and Jelly calculate the number of waffles needed...