How words have changed in meaning and usage over time is frequently a hot topic both on here and the wider community, and I find it fascinating. Are there any good reference works which document this kind of thing?
I'd like to be able to look up a word, and see lists of historical meaning, with periods and explanations. Graphs of changing frequency over time are also great. I don't really want a standard dictionary of etymology, because my perception is that the meaning they concentrate on is the current one, which is interesting but not quite the same, but it could be that I'm reading the wrong dictionaries! I suppose a key difference between this and a very good normal dictionary (my Shorter Oxford does have a summary of previous meanings and examples) is the discussion of the reasons behind the meanings, an idea of the process of change, and some kind of selection by the author (I'm less interested in words that essentially have had one fixed uncontroversial meaning).
I'd prefer a real book, but internet resources would also be of interest. This is the kind of thing where individual examples are discussed in some detail on e.g. Language Log, but I'd like to see similar information collected together. If there's nothing in a "dictionary" format, I'd be happy with a book of hand-picked interesting examples (that might even be better!).