I'm told that Foucault is brilliant as well as crystal-clear in the original French, and that the only reason his work seems so difficult is because all the translations are bad. Seems unlikely, but you never know. I don't know any French beyond that needed for an afternoon in a cafe ("cafe au lait, s'il vous plais", "encore, s'il vous plais", "l'addition, s'il vous plais" -- and I probably didn't spell those correctly), so I couldn't say. I found Foucault completely unintelligible, even when I bought a comic-book version!
I also bought a nice little intro that seemed to be making sense until I got to one part that was just utterly meaningless. I beat my head against it over and over, and finally looked up the passage in Foucault that the author was talking about, and found that the printer had screwed up, mightily: the text said that there were three things, a, b, and c, and started to talk about them, but I couldn't for the life of me figure out the difference between the first and the third thing. Turns out when I found the source, the printer had taken a sentence that referred to a, b, and c, and another quotation later about c, b, and a, and had run them together, deleting all the material in between.
Er, that was clear as mud. Trying again, showing the difference by using upper case. One Foucault quotation said "A, B, and C ARE ALL [WHATEVER] AND I WILL DISCUSS THEM AT LENGTH HERE" and the author I was reading quoted that passage. Then she went on with some discussion and quoted a passage that ran like this "So c, b, and a are all [something else]". But the printer had printed it like this: "A, B, and a are all [something else]" -- and the result was gibberish.
I found the author on-line and pointed this out (as well as a place in the text where the printer had stripped all the paragraphing, so it was one long paragraph that ran for 5 pages), PLUS the references were totally screwy, and in order to keep track, I'd made a list of what the in-text references should have been. I'm afraid I pretty much let the author have it with both barrels, because I was so frustrated.
She thanked me, asked me for the list of problems, said she'd correct them for the next edition. I was kind of hoping she'd offer me a free copy of the next edition, but...no. I was probably too...er...forthright in my criticism.
It was "Michel Foucault" by Sara Mills from the Routledge Critical Thinkers series -- I should go see if there's a newer edition and whether she mentioned me!
Edit: My copy is 2003; Amazon has a 2007 edition, and no, I'm not there. Ah, well. It's not that I have such a high opinion of myself; I forgot to say that she *said* when she asked for the full list of problems that she would acknowledge me.