The first step in taking good notes is having read the assignment before class. If you already know what is being discussed, your notes will make more sense.
The object of taking notes is to record the KEY POINTS being made in class. Don't try to write everything down. Instead, try to understand where the instructor is going with the discussion and then write down those key statements which you will need to recall what was said.
There are several excellence methods for taking notes. My personal favorite is to divide the page with a line, one third on the left and two thirds on the right (you can purchase note pads with this already done). You take notes on the right (two thirds) side of the paper. Later you go back and outline the material on the left side.
If you want to learn more, check out one or more books on study methods from the library... or do a search on the web.
Colby Glass, MLIS