Lukeprog has done some great posts talking about how scholarship has benefited him personally and how to do it. However, he hasn't talked much about how to tell the good from the bad, and I think this is an especially big problem with it comes to "how to"s, rather than standard academic subjects.
The thing is this: writing on academic subjects tends to be dominated by academics seeking to gain status from their work. Not all fields have a strong correlation between status and making actual discoveries, but many (perhaps most) do. So for academic subjects, the big challenge when it comes to making sure you're not reading nonsense is to try to evaluate the soundness of the field in question.
When it comes to seeking out "how to" advice, though, writing on the subjects seems to be dominated by people looking to make money selling advice. That means that if bad advice will sell better than good advice, they'll give the bad advice. Even if their writing includes legitimate advice, they have incentives to give a distorted picture of the subject they're writing on if it will sell better (for example, making whatever they're talking about sound easier than it really is). In some cases, advice books end up trying to nudge you towards buying some more expensive thing the author is selling.
So: when you're researching a "how to" topic, how do you tell the good advice from the bad advice?
Pretty much the same as in the sound academic fields, differing only in the amount of woo, bullshit, and self-interest you'll have to assess. Compare sources, look at results, look at reviews, look at the evidence, ask whether it even makes sense, try things out yourself, etc.
In the area of self-help (as some comedian has remarked, the idea of getting self-help from a book is already something of a contradiction) you also have to contend with the basic therapeutic conflict: anyone selling a cure for a disease has given themselves an interest in never curing it, but providing only palliatives. This is especially true when the disease is an imaginary one and their first task is to persuade you that you have it, which is why so many self-help books begin by telling the reader what a schmuck he or she is.
Here is an extreme example of how not to do it. Conversation I once overheard between a middle-aged man and woman:
The woman: talks about how convenient she is finding her new microwave oven.
The man: "Oh, I've heard you shouldn't use those, they destroy the vibrations in the food."
The woman: "Oh dear, I'd better stop using it then."
Ok, the man's talking woo, but that's not the point here. Substituting a topic more easily able to pass the rationalist filters:
The woman: talks about how wonderful she finds her new bread-maker.
The man: "Oh, I've heard you shouldn't eat bread, it wasn't present in the ancestral evolutionary environment."
The woman: "Oh dear, I'd better stop using it then."
Whatever the facts about eating grains, the epistemic process of transmission here is completely corrupt. So, don't just read a book and nod along to the author's argument, thinking "How true this is, I must do this."
I agree but not sure if for the same reasons. I think most of the time people know perfectly well what they should do differently, they just lack the willpower or motivation for it. A book here may inspire for a short while, if it is really well worded it can "pump" people for a while, but it will not last long. In the vast majority of the cases, people buy self-help book, read actual good advice in (generic good, not big insights, m... (read more)