Unfortunately (or luckily) Foucault’s writing is so broad and encompasses so many areas that quite a lot of his oeuvre could be drawn upon, but then The Archaeology of Knowledge may be the best starting point for what you are looking into:
http://books.google.co.uk/books?id=0sroSLE8ntAC&dq=foucault+archaeology+of+knowledge&printsec=frontcover&source=bn&hl=en&ei=QSolS-DSNsr_4AavmNnrCQ&sa=X&oi=book_result&ct=result&resnum=4&ved=0CBgQ6AEwAw#v=onepage&q=&f=false