This summer I want to try again to do nature journals with my children, 4, 7 and 9. Does anyone have sources for a how-to book and the journals themselves?

Also, I would love to do a super-basic biology or botony study with them. If you have something that has worked for you, please share.:)

I saw this one the other day at a Homeschool fair and thought it was really well done:
Amazon.com: My Nature Journal: A Personal Nature Guide for Young People: Books: Adrienne Olmstead (http://www.amazon.com/My-Nature-Journal-Personal-People/dp/0967245915)

Janice VanCleave books are really good for individual topic studies. Apologia elementary Botany is good too, but it is Christian based.