Are problem solving and student advice books scam? For instance, many people recommend Pólya's or Tao's book, but is it efficient? Would it improve my proof skills? Or would it be more beneficial to open up a textbook and try to prove theorems? Also, University of Oxford has "How to think like a mathematician" by K. Houston and "How to study for a mathematics degree" by L. Alcock on their recommended reading list. Are they good? Are they worth the time? btw, I'm a freshman mathematics major.