Missouri Botanical Garden
Missouri Botanical Garden: Temperate Deciduous Forest Leaf Identification
You identify deciduous trees by the shapes of their leaves. Link to complete tutorial on types of leaves.
Environmental Education for Kids
Eek!: Wisconsin's Champion Trees
Environmental Education for Kids offers step-by-step procedures to measure trees. Designed for Wisconsin's Champion Trees, these guidelines can be adopted for use in any state or area.
Other
Ohio Public Library: What Tree Is It?
An online resource for tree identification by common name, scientific name, leaf, or fruit.