Arnold Lobel books in order
29 books in the catalogue, about 38 hours of reading in all; the shortest takes 35 minutes and the longest 5 hours.
2 series and 20 standalone books in the catalogue.
Frog and Toad
5 books
Frog and Toad Are Friends 1.2 h 
Frog and Toad Together 1.2 h 
Frog and Toad All Year 1.2 h 
Days with Frog and Toad 1.2 h The Frogs and Toads All Sang length not known
Mouse
2 books
Standalone books
Giant John 35 min 
Lucille 1.2 h 
Martha the Movie Mouse 35 min 
The Great Blueness and Other Predicaments 35 min 
Small Pig 1.2 h 
Hildilid's Night 35 min 
On the Day Peter Stuyvesant Sailed Into Town 43 min 
The Ice-cream Cone Coot 44 min 
Owl at Home 1.2 h 
Grasshopper on the Road 1.1 h 
A Tree Full of Pigs 35 min 
Fables 44 min 
On Market Street 44 min 
Uncle Elephant 1.2 h 
Ming Lo Moves the Mountain 35 min 
The Book of Pigericks 53 min 
The Rose in My Garden 43 min 
Whiskers & Rhymes 53 min 
The Random House Book of Mother Goose 3.2 h 
Scary Stories to Read When It's Dark 1.2 h Collected editions
Volumes that gather several of the books above.
Frog and Toad (Frog and Toad All Year / Frog and Toad Are Friends / Frog and Toad Together) 3.5 h 
Frog and Toad (Days with Frog and Toad / Frog and Toad All Year / Frog and Toad Are Friends / Frog and Toad Together) 4.7 h 
Frog and Toad (Days with Frog and Toad / Frog and Toad Are Friends / Frog and Toad Together) 3.6 h