Note-making requires you to select the essential information and to organise it properly. Your notes may be the springboard for an essay or report. It is always better to rely on your own notes, rather than copies of other people's, since you will develop your own patterns of note-making and will know best the points about a lecture or book that interested you.
In any lecture, aim to strike a balance between making notes and listening carefully - try to understand the main points of the lecture and, at the same time, make sufficient notes to enable you to recall each of these points afterwards. There are techniques for effective note-taking that you can learn and get better at. Students often start by trying to write down every word the lecturer says. You will soon find this is generally impossible, and probably not even useful, as you will be missing out on the analytical aspect of note-taking.
Good notes often include headings and subheadings, underlining or highlighting, and clear layout on the page. The more traditional note-making method is linear - with one heading after the other down the page. It is very useful to leave a wide margin at one side, so that you can add extra points later - references, details from your textbook, notes from discussions with lecturers or other students.
Use abbreviations in note-making, but make sure they are clear to you.
Overall you should aim to understand the lecture and your notes should reflect this understanding.