I feel the best thing about LinkedIn is the number of professional people we can connect with. It shows the variety of different professions that you can choose for yourself- whether you are a beginner or an established person, there is always something to learn.
Another very important aspect that I learned from LinkedIn is marketing your skills! I realized that it is not only the professional "marketers" who should have this skill but, in a way, every single person must know how to market their skills well!