This. The ability to Google efficiently is severely underrated.

Do you (or someone) know about any tutorial or a book for learning how to google? Is "how to google" only about phrasing queries, using correct words, improving query using results from its previous version, using quotes, and so on, or is it something more?

Using my google-fu ;) I found this link which may or may not be any good(http://www.googleguide.com/advanced_operators.html).

I have never used operators myself, I think just the way you structure and choose your words wisely has the most impact.

!true! and people don't listen when I tell them to learn and try to google everything before trying to find your own solution. You better improve on what other people already did and thought about

The fact that Googling efficiently is a skill that matters is a clear opportunity for a Google competitor.

How so? Any Google competitor will either have similar syntax (so the "google-fu" will translate and you might as well just use Google), or different syntax (and then you have to learn another search engine who probably has worse results anyways).

(To) Google nowadays is so generalized as to mean "search the internet for something". That's a valuable skill no matter what your engine of choice is.