I'd go by what How To Brew, by John Palmer says. it's a great source of information for beginners.
Expect when he's wrong, and you don't know that he's changed stuff in subsequent editions (like the autolysis bogeyman/long primaries) then you might just want to look at the online discussions are to see what the MOST RECENT thoughts on any given topics might be...what prevailing trends or wisdom might be....
Palmers admitted getting quite a few things wrong, or getting a contrary or different understanding of some things (IBU's) are another example AFTER he wrote the book.
A book is a snapshot of the author's body of knowlege and the "common wisdom" at the time the author wrote the book, which may mean 3 years before it was even published. Papazian's book is 30+ years old. The basic knowlege is good, but brewing science and experience has progressed to where some things an author believes or says at that time may no-longer be valid...even to the author.
John Palmer has changed many ideas since the online version of the book went up several years ago.
And so has CHarlie Papazian.
Most of the time when someone "revises" a book they don't necessarilly "re-write" the entire thing...and unless they annotated the changes, often all a "revised" edition has to make it up to date is a new introduction, and maybe the addition or removal of some things. But Rarely is a revision in a book a serious comb through of the entire book.
For example Charlie, JUST in the last 4 years or so, discovered the idea of using rice hulls in his mash tun to prevent stuck sparges....So just maybe he could even maybe have learned some other things in the last 30 years as well, and just not gotten around to writing about it?
I think just the opposite, that places like this with over 40,000 active participants contributing to the knowlege base, is where the best, most state of the art info can be had. Heck a lot of stuff starts here, that later ends up in the pages of BYO and Zymugy.
Nowadays a book is an old way of gaining knowledge of the prevailing thoughts. It's websites, social media, and podcasts that get updated almost daily is where you glean the latest info on the hobby.
If Palmer farts someone on here will post about it seconds after it happens. We've had stuff mentioned by one of the bigwigs at a conference that is posted here, seconds after and may not appear in writing by the author for a couple months in BYO magazine, so we may actually have had tons of discussions on it before it appears in print.