The first step in planning a lesson is to gather background information on the theme. Use age appropriate resources to find information tailored to their learning level. You can use children's encyclopedias, databases, and informational (nonfiction) books.
Children's Illustrated Encyclopedia
Call Number: Curriculum Reference 031 C5368
This is a good place to start for background information. There will be general information written for a younger audience. This helps to know how detailed to be in your lessons.
What's Inside a Flower?
The nonfiction section is a good place to find books for background research. They are meant for different age levels and can show you how detailed to be on your topic for a particular age range.