For some older adults, computer jargon such as "logon," "e-mail" and "download" might as well be in a foreign language. But that's not the case for 4,000 computer-literate seniors who participate in SeniorNet, a nonprofit organization that helps the over-55 set enter the information age.

At 39 locations in the United States and Canada, SeniorNet members receive instruction in word processing, data base management, spreadsheets, desktop publishing and telecommunications. The $25 annual membership fee includes free classes, a quarterly newsletter, discounts on hardware and software, and a copy of the book "Computers for Kids Over Sixty."Some SeniorNet members have put their new skills to creative uses. Howard and Dorothy Hamm of Syracuse, N.Y., coordinate a group of 12 older adults who teach computer classes to first- and second-graders at a local elementary school.

If you have a modem, you can also connect your home computer to a network for seniors. Members use the network to communicate with other members around the country, to track investments or to participate in forums. Monthly user fees are $5.70 per hour during evenings and weekends and $14.70 per hour during weekdays. You can get 20 hours' worth of evening and weekend use for $20 a month. Contact SeniorNet at 399 Arguello Blvd., San Francisco, CA 94118 (415-750-5030), for a list of teaching sites or a membership application.