When you tire of spending money on your computing hobby where you live, try telecommunications - it will allow you to spend money in places you've never been. But first, spend $19.95 and buy "The Modem Reference" (Brady Books-Simon & Schuster).

The book by Michael A. Banks of Milford, Ohio, is written for the average person who just wants his computer to be able to make telephone calls to other computers, which is what telecomputing is all about. If you can't find the answer to a telecomputing question in this 500-plus page paperback, there probably isn't an answer.Equipping your computer for telecommunications will give you access (for a fee) to databanks, services, entertainment and companionship on a transcontinental scale. You may, for example, use one of the large commercial databases such as CompuServe to check stock quotes, buy merchandise, read the news, download software and "talk" with others thousands of miles away.

Or your interests may be out of the ordinary, say in things that go bump in the night - in which case you'll want to log onto one of the systems in ParaNet, a network devoted to exploring the paranormal.

You even might, given a good boss and the right kind of business, work at home, using your home computer to access the main computer at the office.

But before you can do any of these or thousands of other things, you've got to buy and install a modem, make it work and convince it to speak properly to other modems. That's where Banks is so handy.

A modem is a widget that "talks" by turning the pulses of electricity that your computer understands into the varying tones that the telephone system likes. It "listens" by reversing the process. If that's all you need (or want) to know, go to Page 59 of the book and read the chapter on modems, including a comparison chart for some intelligent shopping.

But if you agree with the author that, "You don't have to understand how something works to use it, but understanding sure makes things easier - especially when trouble pops up," then go to Chapter 3 and find out just what happens when all those electrons in the modem start to play tag. You'll get concise, illustrated explanations of what makes things tick.

That format of telling you what button to push and adding (if you're interested) an explanation of what happens after that, makes the book readable for more than reference. While it's not something to curl up with on a dark and stormy night, the well-written explanations can hold your interest longer than a typical techie manual.

For those who would like to get an overview of what's available in the world of on-line information, the book's third section covers everything from private bulletin board systems (BBS) to the giant commercial consumer and business networks.

If you're interested and don't find a copy at the local bookstore, try writing Order Department, Brady Books, Simon & Schuster, Gulf & Western Building, One Gulf-Western Plaza, New York, NY 10023. If you have other questions, the author can be reached by writing Michael A. Banks, PO Box 312, Milford, Ohio 45150.