There's a temptation, when you're an early-stage startup with little direction, to start "playing house"[0]: Trying make your startup look and feel like all these other successful startups you've seen, and, by reading more books, getting positive feedback for doing those things.
There's obviously value in wisdom gained from those who've walked down this road before. But it's not worth obsessing over how to make the perfect startup. It is worth obsessing over how you can be delivering more value to your customers.
[0] PG's term http://paulgraham.com/before.html
Topics would include "fundamentals" like different ways to talk to customers or different ways to test product-market fit (possibly in a very efficient way). These may seem very obvious to people who have done them or know someone who has, but they are not obvious to a lot of people.
I will also add that once product-market fit is achieved and the business is officially a thing, there are a wide range of readings that would be useful for a (relatively) new founder. Topics would include things like sales, fundamentals of management (this topic is really not obvious or widely known to a lot of young, gifted people who are often founders of decent startups), and basics of business operations. Granted most of these things can be found on one's own, but a tight, curated list (this one does not seem to be one) would certainly have some value.
Note to the budding startup founders out there: Reading in moderation is fine. Always read for a purpose. Stay away from the startup porn -- it will take you down a path of failure.
Personally, I don't track time spent reading, unless it's to understand how to solve a specific problem.
I think the great majority of people should read these books - in a matter of hours they can be a fly on the wall. Mistakes cost money and time. Also, most people aren't around people who have had success in this avenue, so being 'around' the authors does help to make their goal real.
Product always goes first.