A comprehensive 5 volume set exploring ethical issues in biology, medicine, and othe life sciences. A three volume set outlining the fundamental concepts and issues related to ecology and environmental science. A well illustrationd guide to evolution and natural selection, providing basic information. A general guide to the biology of our species. As you might expect, there is considerable medical information provided, as well.
Essays are excellent introductions, and many are quite lengthy.
One of the standard dictionaries in biology. It includes descriptions of chemical structures and elements, as well as outlining of scientific classifications. A comprehensive, if concise, guide to plants and animals.