There is a useful website to accompany the 4th edition. It includes study questions.
Other useful texts you could consult:
Futuyma, D.J. 2005. Evolution. Sinauer. I might use this in future years, so if you use it, let me know what you think. This is a somewhat simplified version of Futuyma's Evolutionary Biology (3rd ed.) which was perhaps the most authoritative and encyclopedic text.
Ridley, M. 2004. Evolution, Blackwell. More discursive than the others.
There are many outstanding books (and shorter readings) on evolution, many written for a non-technical audience. I will list a number of them here as the course progresses.
Why study evolution?
Palumbi, Stephen. 2001 The Evolution Explosion: How Humans Cause Rapid Evolutionary Change. W.W. Norton. Rapid evolution and its practical consequences.
Dennett, Daniel, C. 1991. Darwin's Dangerous Idea. Simon & Schuster. A philosopher explains why he thinks evolution by natural selection is the best idea anyone has ever had.
The evidence for evolution.
Futuyma, Douglas J. 1995. Science on Trial: The Case for Evolution. Sinauer.
Isaak, Marc. 2005. The Counter-Creationism Handbook. University of California Press. Point-by-point rebuttals of creationist arguments, with references.
Kitcher, Philip. 1982. Abusing Science: The case Against Creationsism. MIT Press. A prominent philosopher's take on the subject.
Orr, H. Allen. Darwin Versus Intellingent Design (Again). Boston Review http://www.bostonreview.net/br21.6/orr.html An evolutionary biologist reviews Behe's book on intelligent design.