This chapter is a major overdose on the Hertzsprung-Russell diagram. Its a popular diagram in astrophysics, and by the end of this chapter, and a few subsequent ones, you'll feel right at home with it. It looks at the location of the main sequence stars, like our Sun, which is towards the more insignificant end of the chart. Also at things like Red Giants, SuperGiants and white dwarfs which fall off the main bad somewhat.
You also pick up a few other lesser known types, such as Cephids, and T-Tauri stars, which turn out to be a bit more important later on.
After the H-R diagram has been done almost to death, the remainder of the chapter focuses on the interstellar medium and its affects on observations.