Stack Overflow Considered as a Grimoire or Trove
Back in the day, when I came upon a particularly juicy tip/hint/trick/kludge/etc. I would write it down somewhere (way back -- in a paper notebook; more recently, somewhere like TiddlyWiki). But I don't do that anymore -- why?
The answer is Stack Overflow. When I have a question, a web search often has 1 or more Stack Overflow answers at the top - answers that usually help me fix (or work around) the problem I have. It really is impressive how often Stack Overflow has just the answer I need and in just enough detail. (Disclosure: I answer questions on Stack Overflow on a semi-regular basis.)
Stack Overflow could be considered as a grimoire (in the "Wizard did not seem to be a career choice, so I chose programmer" sense). Many dusty, ill-lit corners of languages and systems have been brought to light by the helpful folks at Stack Overflow in both the answers and the comments. I don't know much about the beginner's questions on Stack Overflow or on the other Stack Exchange sites, but the questions I have day-to-day on programming are often answered in full on Stack Overflow. The breadth and depth of coverage is a quite an astonishing feat, especially having achieved this coverage in such a relatively short time.
A shout-out is also deserved by the other Stack Exchange sites -- Superuser, Ask Ubuntu, english.stackexchange.com, etc. etc.
Somewhere around our house is a picture of my cubicle circa 1995 - strewn with magazines and articles comprising a badly-organized and incomplete treasure trove of tricks, kludges, hints, clues, inklings, indications, etc. etc. necessary for quickly solving the problems whose solutions are not in the back of the programming book(s). Nowadays, my workspace is clean and uncluttered due in no small part to Stack Overflow and the other members of the Stack Exchange family of websites. This is not just a Good Thing - this is an advancement of the state of the art, and ask your local Ph.D. just how easy that is. Just as a little photography and a little materials science led to the Computer Revolution, a little amateur sociology, a little Information Retrieval, and a little programming led to the English-speaker's worldwide knowledgebases - Stack Overflow et.al. Kudos and laurels to the Stack Exchange team along with the many, many contributors.