To make study notes, listen to the material or read the textbook, determine the most important information, and write it down. It is best to write down only important key words, definitions, dates and formulas. Don't try to write down everything without trying to understand the material. Use legible shorthand to write down more material, or to have more time left to listen and understand.
Another good method for taking notes is called the "question, answer, evidence" method. Don't try to write down the information; instead, listen to the lecture carefully, and try to understand the material. After that, come up with questions about the material, write them down, and fill in the answers. Back the answers up with some evidence, and write it down below the answer.
Before writing study notes, make sure you have all of your note-taking materials ready, go over your notes for the previous chapters, do all the background reading that is required, and write an outline for the new chapter.
Take notes by hand instead of using a computer, as it generally helps students to remember the material better. If you don't understand something, ask your teacher a question, because it is going to be much harder to figure it out later on your own.
It is easier to study the notes if the writing is easy to understand, and the notes are structured and include tables, lists and diagrams. Highlighting the most important information also helps, as it activates the visual memory.