What are the best basic biology texts?

I have been trying to acquire a strong understanding of the basic sciences but have had trouble finding good books on biology. I understand very little biology as it is. I'm not looking for a textbook or anything that is geared towards a cl. I have found books about physics and chemistry which are exactly like what I'm looking for (about a thousand pages, both under $15, and they leave the reader with an understanding of these fields equivalent to if they had taken an entire intro series in them in college for a year) in Issac Asimov's Understanding Physics and Linus Pauling's General Chemistry. I am trying to find the equivalent to these in biology. Thanks for your recommendations!!!