I was thinking for a new category called Book suggestion (not only book suggestion either). Usually, most of Science students like to study Science books (their favorite subject) by themselves. Some of them self-study rather than getting to University. And, some of them looks for book suggestion. If professional "students" (Physicist) suggest book than, "we" could get perfect book. So that, we can learn easily also.

Usually, Physics is interesting subject. Most of School and College students fell in love with Physics (:D :P). Some of them start by studying very higher theories but, when they think that they should start from beginning then they starts from Classical Mechanics. And, some people thinks "Should I study Quantum Mechanics/Relativity/String theory now?"

When looking for book suggestion they can add further information either. (Like) I have studied Classical Mechanics,"Should I study Lagrangian now"? I have studied Lagrangian, Hamilton, Relativity, "should I study Quantum Mechanics now?"