Read Chapters 20-22 from Discovering Astronomy.
WebAssign -- Chapter 20-22. Answer homework questions covering Chapters 20-22.
Chapters 20-22 describe our own galaxy, the Milky Way, as well as galaxies in general. Chapter 22 describes quasars.
The individual stars that we see in the night sky are ALL in our own galaxy. If you are fortunate to have a dark sky, you can make out faint fuzzies such as the Andromeda Galaxy or the Large Magellanic Cloud or Small Magellanic Cloud. These are the only objects visible with the naked eye that are outside of our own solar system. And they are galaxies. All other objects that you see with the naked eye are in our galaxy.
If you trained the world's best visible telescope so that it looked away from the disc of the galaxy and into a seemingly very dark part of the sky where there are no stars, what would you see?
The picture above is called the Hubble Deep Field image. Every object you see in this picture is a galaxy! At the HubbleSite, you can read more about this picture.