Frogs and Toads in Sounds and Color
Glass Frogs
Jumping into Frogs and Toads, A Web Quest for K-2
Exploratorium:  Frogs
Frogland
The Wild Ones
Frog Dissection Kit

Frogs and Friends

Literature About Frogs:

Frogs by Nic Bishop

Too Many Frogs by Sandy Asher

A Frog in a Bog by Karma Wilson