If you want your children to become good scientific observers, a great place to begin is with leaf and tree identification. (You could start with birds, but they don't stay put for observation. Plants are easier than birds, but more complex than trees.)
This kit includes an illustrated, full-color, 96-page leaf and tree guide, with a 64-page leaf collecting album, and a plastic carrying pouch for collecting leaves. Major leaf and needle shapes are described along with over 100 common trees. Children learn about the life cycle of trees and how to press and mount leaves they collect from their tree observations. They also learn how to use leaf features such as the shape and edge patterns to make their identifications. Related activity suggestions are included. This is recommended for children ages 5 through 10 who are just beginning their study of trees.