I'm considering reading the book by the title How to read a book. A friend of mine (his critical thinking is quite good, but certainly not as good as it could be, so I can't trust his opinion too much) said he has read it and that it helped him a lot. He said it had advice on reading comprehension, critical thinking ("don't automatically accept what you read") and that when people read something, they tend to forget it quite easily (and that the book addresses this issue). But he also quoted a part of the book, which said that only reading hard things will improve your reading - it might be true, but it doesn't sound intuitive to me (according to my rationalist intuition, obviously :D). Also, the book is written in 1940 and revised in 1972. Additionally, the author is religious (I think he's even highly religious). And if I remember correctly, it's not based on research - there is a quite high chance that I don't remember correctly. I checked its Amazon page, nothing said anything about research (browsed through all the low ratings to see if they complain about that, nobody did).

Should I bother reading it? If it delivers what it promises, it will obviously be so cost-effective that most rationalists should abandon reading whatever they're reading and switch to this book. But is there a version that is entirely based on research, with references or sound theory behind most claims?