When she completed her junior year of high school in June, Sharon Lessans said the last thing on her mind was going back to a classroom. But after what she described as "strong encouragement" from her mother, Lessans, like hundreds of other area teen-agers, decided to spend part of her vacation attending a college preparatory course.

"Now I'm glad I did it," said Lessans, 17, who will be a senior at Springbrook High School in Silver Spring this fall.

In classrooms from Baltimore to suburban Virginia, a growing number of students are taking time from summer's social life and jobs to prepare themselves for the transition from high school to college. Many teen-agers get nervous just thinking about college. So they are taking classes--lasting from two days to four months and costing as much as $110--to improve their study skills and ease their anxiety.

Lessans and 20 other area students enrolled in the College-Bound Program at the University of Maryland's reading and study skills lab in College Park.

One of the longest and most individualized preparatory courses offered locally, College-Bound gives students four weeks of instruction in such skills as time management, test-taking strategies and exam preparation.

"This isn't like high school at all," Lessans said. "In high school everything is very structured, but this is more independent. It gives you a taste of what college is really like."

In addition to attending two-hour seminars three times a week, students are required to complete a minimum of 10 hours of independent work, particularly in areas in which testing has shown them to be weak.

Gerard Donahue, 18, spent last week working on his vocabulary and speed reading. "I knew I needed help in improving my English and study skills," said Donahue, who plans to attend the University of Maryland this year. "In college you might have to read 20 or 30 pages a night for just one course, and this has given me a lot of confidence."

Shirley Browner, College-Bound coordinator, said most students who attend the program "are average to above-average students but most of them have some concerns academically. Perhaps writing has always been a problem or sometimes they are just trying to improve their SAT Scholastic Aptitude Test scores."

But the instructors stress that their programs are not remedial courses for basic high school subjects. "We're just trying to help them sharpen their study skills for college," Browner said.

In addition to formal instruction, college preparatory courses include practical advice and tips on how to avoid academic problems. On the last day of College-Bound's formal session last week, the participants heard from University of Maryland students.

"There's a big adjustment from high school to college," said third-year public relations major Nancy Raimondi. "When you are in high school no one wants you to be an adult, but you have to understand that freedom means responsibility."

"In high school you'll do your homework maybe once a week," Angela Grimes, a prenursing student, told her audience. "But here there is more on you and you have to be more organized. Otherwise, it's only when test time comes around that you find out you're in trouble."

Time management is one of the most popular topics at college prep seminars and one strongly emphasized by instructors.

"It just makes you think about how you go about studying," said Phil Alcorn, 17, who attended the two-day College Success Seminar at George Mason University last weekend. Designed by a California psychologist and conducted by the University of Maryland's University College, the seminar is a 16-hour blitzkrieg of lectures, drills and practical advice.

"Half of what they have been telling us is the same stuff my mother has been trying to tell me for four years," said Andy Hutchison of Leesburg. "I guess it's just easier when somebody else tells you."

"A lot of this material is just common sense," said seminar instructor Michael Cain.

Cain, who is working on his master's degree in philosophy at the University of Maryland, said he became interested in teaching the seminar "because I was angry at the way professors were teaching. They don't tell students what is important in a course or how they should study for a test. The university should have this course for all incoming freshmen."

Students about to enter college for the first time are not the only ones attracted to college preparatory courses. Jane Johnson, a mother of two teen-agers nearing college age, said she attended the College Success Seminar because she recently became interested in computers while working as a volunteer at Oakton High School and is returning to college.

"I wish I'd taken this earlier," said Johnson, who already has a master's degree in education. "Some of this I have learned for myself by now, but it was very interesting and more than I anticipated."

Johnson and Joan Crooker, another Northern Virginia woman going back to school, said the sessions on study skills should be an important part of a good high school curriculum.

"For kids just starting, time management and establishing a daily routine are very important," said Crooker. "For me 25 years ago, I didn't have these things. I didn't learn how to properly read a textbook until I was a junior in college in 1973. Why was it necessary for me to wait until I was 31 for someone to tell me these things?"

Somewhat dazed after two consecutive days of being inundated with so much useful information, many students at last Sunday's seminar said their biggest worry now is following through.

"The hardest thing is going to be doing all this," said Mia Tharp, who is headed for Pennsylvania State University this fall.

"I'll probably work out all my schedules and follow them for the first two weeks and then forget about them," said Kira Liebenberg of Chantilly.