Books for sale on random street corners? Stranger things have happened. Bargain hunters and lit lovers know where to find unofficial purveyors of all things prose come the warmer months. Titles range from the classic (think Charles Dickens), to the trashy (Danielle Steele) to the downright bizarre (the book on whittling looked like it had been sitting there for a while). Though they’re sometimes difficult to catch — it’s not like they keep regular hours — a steady bet is the corner of Madison Avenue and Bloor Street on weekday afternoons. Book collector J.C. likes to set up shop between 4 and 8 p.m. and typically sells his wares for $3 a pop.