I am working my way through Carl Sagan's book The Dragons of Eden, about the evolution of the human brain. This is my choice for "light reading" after finishing my Biochemistry class. (I have my next textbook for Advanced Analytical Chemistry, but haven't done more than page through the table of contents.)
Dragons of Eden is great for keeping my brain alert during my time off from school. Biochemistry was quite a challenge but will surely help my understanding of things such as environmental toxicology, in the future. I also learned a lot about food additives while researching the ingredients in bread for extra credit.