The Great Kapok Tree is a fun book that talks about the rain forests. This could be used for a geography lesson. This book also talks about the different wildlife and their habitats so it could also be used in science.
"Over in the Jungle: A Rainforest Rhyme" - Great set of books about nature, animals, habitats, etc. by Marianne Berkes. All books set to the tune "Over in the Meadow" .great for core & connections to other subjects
"Encyclopedia of Rainforests" by Diane Jukofsky -- Explore the magic and mystery of the world's tropical rainforests in this fascinating volume that brings to life the plants, animals, and people that inhabit this fragile ecosystem.