If crafting is your thing, check out Nature Craft by Fiona Hayes. The great thing about this book is that many of the supplies you need are just outside your door. Rocks, sticks, pine cones, pieces of bark—all found in nature and free to be used by budding young naturalists. You will also need some supplies not found in nature, but those items could be things your already have such as glue or paint.
Whatever you make, you are sure to have fun and your nature craft will be one of a kind.