Speaking of writing books about stuff, communication equipment would be probably of an equal or even higher priority to sanitation since efficient information transfer will greatly speed up the re-engineering effort. Furthermore it wouldn't be terribly difficult to do early on. You don't need too much metallurgy to cast type, and the rest of a basic letterpress could be made of wood. Paper isn't too hard to make. Neither are batteries, so as soon as you can produce wire efficiently you can set up a telegraph. Telephone, radio, typewriters, Linotypes, and lithography would all require more mechanical sophistication, so they can wait a bit.