How do I install bolt-on furniture legs?

Recently, I bought four short, turned furniture legs from a home center, but hit a brick wall when it came time to install them. How do I attach the short (³⁄₈ " long) threaded studs to my bookcase? There were no instructions included with the legs.
—Henry Watkins, Columbus, Ohio

You'll find the solution at most hardware and woodworking stores, Henry: threaded inserts. Begin by measuring the diameter of the threads, as well as the diameter of the barrel (as if there were no threads). Then drill a hole with a diameter about midway between those measurements, deep enough to seat the insert. (Do this on a drill press, if possible.) Next, install each insert as shown above. Finally, thread the legs into the inserts.