A.Gary Katz responds: I feel your pain. Finish carpentry, especially door hanging, is a tool-heavy trade. Here's the best advice I can give to any part-time door hanger.
First, put together a good door bench or a door stand. You can cobble a stand together from some scraps of 2-by and 1-by, or you can make a full-blown bench. I'd suggest making the bench. A good door bench has a lot of uses. The legs fold up, so the bench is easy to store and transport, and once you start hanging doors, you'll never stop — there's good money in it. (See "Hanging a New Door in an Old Jamb," 8/99, for more on building a door bench.)
But it's the tools that cost real money. I'm figuring you already own a good-sized drill, a cordless driver, and a circular saw, so a plane might be your most expensive purchase. As a full-time door hanger, I prefer a Porter-Cable 126, which is sold in a kit, #9118, for about $400. For just a few doors, you can also use a regular plane, like the Bosch 1594K, one of the few multi-use planes equipped with an adjustable bevel guide ($155 on the web).
You might be able to avoid buying a plane altogether if you can purchase prebeveled doors. We use them all the time.
You'll also need a router. For door hanging, I prefer Porter-Cable's 7/8-hp model #100, which, unfortunately, may have been discontinued. For a multipurpose router, I'd suggest a Bosch 1617evs ($170 on the web), which has a micro-adjustment knob as well as a quick-change template guide system. You'll need that template guide because you'll have to use templates for mortising hinges and locks.
I buy all hinge templates and most lock templates from Templaco (www.templaco.com) because they cost less to buy than to make, and Templaco's templates are always dead-on accurate. For those 1 3/8-inch doors on your job, you'll only need a single-pocket template (Photo D) for 3 1/2-inch hinges ($20). If you're hanging new doors in new jambs, you can get a full-length template that lays out all three hinges.
For boring doors, you could buy a good-quality hole saw for the cylinder and a spade bit for the edge bore, and live dangerously! But if you can, when it comes to boring doors, break the bank and go all the way. Templaco sells a couple of great kits (BJ-115 or BJ120, about $370) that include all the latch and strike templates you'll ever need, plus the boring jig (Photo E) and bits. If you bore more than a dozen doors a year, think about upgrading to their carbide spur 2 1/8-inch bit ($127). You'll never regret it. (See "Installing a Cylindrical Latchset," 12/00.)
These are only the basics. When you're ready for flush bolts, mortise locks, and auto-bottoms, contact me at JLC Online's Finish Carpentry Forum and I'll tell you more.
Gary Katz is a frequent contributor to JLC, author of Finish Carpentry, and moderator of JLC Online's Finish Carpentry Forum.