Secrets of small things
At first sight this book , published in 1962 and 1976, looks deadly dull - masses of text and no colour, only a lot of black-and-white line drawings. But that first impression is totally misleading.
The text is clearly written, suitable for children 11 or 12 years old through adults, and the illustrations are just what is needed. This book tells fascinating tales about what we can see in a large number of plants and animals, and a few minerals. I doubt that there is any better introduction to the wonders of nature.
A practical hint - Get one lens with a magnification of about 5x, and a second one about 10x. Higher magnifications are difficult to use.