I guess it's training. In german we have a word for it that translates to "media competence", something way not enough people have.
It contains several things (some already mentioned before):
- learn how to search, good and bad phrases, etc.
- over read all the pages that look like crap (only gained from experience)
- never trust one source, always double check, maybe with a different search engine
It hardly depends on the topic you want to research and mostly depends on experience.
Back in m guitar days I used https://www.911tabs.com/ And https://www.ultimate-guitar.com/
The last seem to try to force into member ship now, but the first still looks to be free and some years ago most things were printable