If you learn something like haskell from books instead of blogs, the explanations are usually much much more comprehensive and cogent. Both Learn You a Haskell and Real World Haskell are excellent in that respect.
I find more and more that blogs are great for discussing things you already have deep knowledge of, or of finding leads to resources for learning them (book recommendations, etc.), but there's no comparison to books for really learning something well.
Blogs are just too piecemeal, and the articles are usually written in a few days or a week, versus up to a year or more for books. Hence the quality of pedagogy is just much higher with books than blogs.
I found Learn You a Haskell unexciting; it was more useful for me to hang out with my Haskell-programming acquaintances, read a lot of code, and get my hands dirty using it than it was to just read and play with examples.
Even as someone who writes a technical blog, I'll agree that blogs aren't the best medium for disseminating learning materials. That's what proper online documentation and books are for: specialised topics, in long form. I can write 50 1000-word blog entries and help people on more topics, but fewer people per topic, or I can write one 50,000-word book and reach many people on just the one.
Yeah, blogs are great for discussing edge cases and the like with people who already know the topic, that books don't have room to cover.
And of course, neither books nor blogs nor language references, etc. substitute for actually sitting down and programming something challenging. But they can help reduce the amount of initial time wasted on trial and error, get you using the language idiomatically, and get you up to speed on language-specific best-practices faster.
Not to mention field reports getting something working - especially useful when an API of a library is not so obvious and the documentation is lacking. EG Rails-centric documentation but using Sinatra.
Although the time could arguably be spent more productively improving said documentation, sometimes an informal tone (which may not be appopriate in docs) can help to dissolve frustrations..
I find more and more that blogs are great for discussing things you already have deep knowledge of, or of finding leads to resources for learning them (book recommendations, etc.), but there's no comparison to books for really learning something well.
Blogs are just too piecemeal, and the articles are usually written in a few days or a week, versus up to a year or more for books. Hence the quality of pedagogy is just much higher with books than blogs.