Have you tried reading any of those books

I've read excerpts from some of them.

There is literally a whole job and science area dedicated to it. I don't see how common sense would be better than a book written by a professional on the subject.

If you have a research paper on, then I wouldn't call it self-help. That's simply a specific manual on. Also, especially in the case of "applied" applied sciences, you should always question the validity of the results. This is the case as you don't always have rigorous data treatment in these fields of study, and questionable methodology.

can be a starting point to go look for more advanced knowledge on the subject

Sure, but do you really need a book to tell you where to look further? Don't parents and schools teach children basic skills in finance, relationships, health, etc.?