As a student you spend a lot of time reading and taking notes in order to learn new subject matter and retain knowledge. Your efforts are more likely to succeed if you approach reading and note-taking in an active manner.
Active academic reading is a structured approach you can use to make sure that you spend your reading time optimally. This happens by taking your current needs as a learner into consideration.
When taking notes, there are many techniques to choose from, but no rules. So practise guerilla-style note-taking: try out the techniques, blend them, and adapt them to suit your needs.
Before you start, it is a good idea to consider the purpose of your reading or note-taking.
Why are you reading a particular text? What will you be using it for? How and when do you expect to use the notes you are taking?
When you have identified your purpose, you can decide how much to focus on getting a general overview, and how much to focus on understanding the details.