Our older children are learning about the rainforest biome which includes mapping, the four layers, the animals, the plants, and the products. As soon as the younger children saw the brightly colored animals, they wanted to learn too.
In the course of my internet search, I found a set of rainforest animal matching cards at http://www.abcteach.com/free/f/flashcards_rainforest_mix.pdf . I printed two sets, cut them out, mounted them with rubber cement onto construction paper and recut around the edges making a colorful edge and double thickness for durability. A perfect game for preschoolers! Books we found helpful were:
Rainforest Babies by Kathy Darling
Predators in the Rainforest by Saviour Pirotta
Find it in the Rainforest by Dee Phillips
People of the Rainforest by Anna Lewington and Edward Parker
Living in a Rainforest by Allan Fowler
Does it Always Rain in the Rainforest? by Melvin Berger