Free advice for writers: When you're editing your manuscript, circle each "it" with a big red pen. If there is any chance that a reasonable reader will reach an "it" and then have to back up to figure out which of two (or more) things that "it" might refer to, replace the "it" with something specific. Don't make your readers re-read. It breaks the flow, and draws attention to your writing instead of your subject matter.
Today, on an inspired whim, I tried Kinkos (a U.S. copy shop) on-line printing. You upload a document (a PDF, in this case) to their website, specify how you want the documented printed (b/w, double-sided, on 20 lb. stock, spiral bound), proof it using their nifty web-based document proofer, give them a zip code and a credit card, and they tell you when and where to pick up the result (2 hours later, at a Kinkos 3 miles away). They do charge for the service, but it seems reasonable ($22USD for a spiral bound, 125 paper page document, printed double-sided). It's a big win on hassle factor, though figuring out how to get my printer to do double-sided is still on the list of "shoulds", along with cleaning out the garage and remembering to floss daily.