I have finished the promised essay on puzzles. It is ... quite long. It can be found here:
https://docs.google.com/document/pub?id=1EJreEaPYmkbaNqZDwlZYhzVfLC1DqxTzeSYE1O5p5QU (I had originally intended to publish it on LJ directly, but making future edits will be easier if I only have to do it in one place.) Please leave comments/questions/brickbats/etc. on this post.
EDIT: If you hate the formatting of that version, try this one:
https://docs.google.com/document/d/1EJreEaPYmkbaNqZDwlZYhzVfLC1DqxTzeSYE1O5p5QU/edit Being inside Docs instead of "published to the web" means it respects my margins and line spacing properly, at the expense of being, well, inside Docs.