What you need to know for the exam is written in paragraphs. The images and YouTube videos are meant to reinforce the concepts on the exam. The quizzes at the end of the tutorial are meant to test your knowledge on the topic. These questions come from the actual exam released by U.S. Citizenship and Immigration Services. Keep in mind that only ten of these will be asked and you only need to get six correct to pass. However, the questions picked by the officer are completely random so best that you know all of these.
The tutorials and quizzes can be taken in any order, no need to start with the first topic if you already have a pretty good undertanding of the principles of American democracy. Remember to also listen to the Audio files, especially if you have difficulty reading and/or writing English. The audio files are very clear and will help you out tremendously since an officer will verbally ask you the questions.