Check out Homeschool Freebie of the Day: To join me in downloading "THE FIRST BOOK OF STONES (PDF ebook)
A wonderful introduction to collecting and studying rocks, minerals and fossils for children, with many hand-on activities, field collecting advice, and hundreds of illustrations.
Note: This book was published in the 1950s, and is not written from a creationist viewpoint. However, discussion of the age of the earth is minimal, with only one two page spread. There is a LOT of excellent practical teaching material in here, so please just be willing to glean a bit if you use this resource.