PRINCETON, N.J. — Ryan LaSalle learned how to use electronic mail on his first day at Princeton University.

Caryn Siegel waited until her second year after realizing it let her easily communicate with a friend at another college.

The PC in LaSalle's dorm room checks with Princeton's main computer every five minutes for new messages. Siegel logs in once or twice a day on public machines in academic buildings or one at the Student Volunteer Center.

"All over the campus, no matter where you go, you can always get E-mail," she said.

Like Princeton, most colleges have become wired societies, already transformed by computer-assisted communication in ways that will take the nation as a whole years to achieve. They are the first to experience the promise of the digital age in social as well as productive behavior and the first to tackle its problems.

"We are ahead of the curve," said William Graves, associate provost for information technology at the University of North Carolina. "We have a lot of experience with this. It would certainly be a shame if the nation didn't take advantage of it."

More than 80% of the nation's colleges, universities and junior colleges are linked to the Internet, the network of computer networks formed in the late 1960s to join collegiate researchers with the government and military contractors.

Most of those schools provide every student with a computer account that is an address on the Internet, a practice that became common about five years ago as more students brought PCs to campus. Many have also linked their residence halls and academic buildings with high-capacity fiber optic lines.

The Wired Life

As a result, students in most colleges think nothing of accessing the school library's index or one at another college from their own dorm.

Many schools foster a sense of community by creating topical discussion areas on the campus network similar to those on the Internet or commercial on-line systems like CompuServe.

Many also use computers to distribute campuswide notices. Princeton, for instance, sends its newsletter on outdoor activities and trips via E-mail, saving more than $5,000 in printing.

And a small but growing number of professors require students to download assignments or turn in homework through the campus computer.