What are some signal words and how can looking for them you take better notes?

Signal words are those words that give hints about what to expect next when reading a text or when taking notes. Understanding signal words help to improve one's comprehension. Examples of signal words are: therefore, furthermore, because, hence, for this reason, however, firstly, finally, meanwhile, ultimately, etc. 
Looking for signal words can help you to take better notes because, it points to the essential facts of the notes and help you to summarize only the important facts of the note. Signal words also points to the main ideas in the topic under consideration.