I find Paul Graham's essays & Brian Balfour's essays very insightful.

PG --> http://paulgraham.com/articles.html BB --> https://brianbalfour.com/essays/

I also follow YCombinator's podcast & Startup School Videos to glean what anecdotes I can find on getting users & finding product-market fit. [https://www.youtube.com/channel/UCcefcZRL2oaA_uBNeo5UOWg]