Brown University senior David Smith and 1990 graduate Jennifer Wilcha both say they love their alma mater and wouldn't think of attending any other institution, but they have spent most of the last year talking to transfer students and admissions officials across the country.

Now, they say they know everything there is about changing colleges, including the fact that one of five undergraduates transfers and that many switch schools more than once.

"We're both really into transferring now," says Smith, a literature and society major. "We learned an incredible amount about institutions and students and the importance of knowing what resources are available."

Smith and Wilcha just published "The College Student's Guide to Transferring Schools," a blow-by-blow explanation of when, how and why to switch schools. It is the first college how-to book targeted for transfer students.

"Students are not really well-acquainted with the kind of criteria needed for transfer admission," says James E. Christensen, associate dean of admissions at the University of Maryland, at College Park, which accepts 3,500 transfers a year. "They are so schooled in freshman criteria that the transfer criteria come as a surprise."

Admissions counselor Dewitt Powell of Howard University agrees. "Transferring is difficult if you have not done your homework," he says. "The list {of things transfers need to know} is probably almost endless."

Smith and Wilcha based their research on questionnaires filled out by hundreds of university admissions offices across the country and on interviews with scores of transfer students, college officials and education experts.

The book combines profiles of transfer students with chatty, practical advice on topics from transfer credit to housing and financial aid for transfer students.

Its stresses the importance of visiting a school and talking extensively with both students and faculty before applying to transfer there; sitting in on classes at a potential new school and ascertaining that the institution offers courses of study that are appropriate for the applicant.

"Those are good recommendations," says David Gibson, associate dean of admissions at Georgetown University. He adds that, though in his experience transfer students adjust easily, a market for "The College Student's Guide to Transferring" exists simply because of the sheer numbers of students who switch schools.

Other advice in the book ranges from the amusing to the practical. Smith and Wilcha relate how one student told admissions officials at Harvard University that he hoped to transfer to that school to study existentialism. Harvard offers no courses in existentialist philosophy, and the student did not get in.

"We were surprised at how people didn't prepare," says Wilcha, who majored in ethics and political philosophy and now is producing a video on safe sex practices.

"People hadn't thought about transfer credit, about housing," Wilcha says. "They hadn't visited ... I mean, if you hated it the first time, shouldn't you do some research before trying it again?"

The guide gives suggestions about how to beat the system as well: Smith and Wilcha suggest that students take a leave of absence, rather than terminate enrollment at their original schools, in case the transfer doesn't work out.

If a course you took at the old institution has no corollary in the new one, they say, call the first course an "independent study" in hopes of getting transfer credit.

The guide stands out because of the youth of its authors, as well as its subject matter. Smith is 21 years old, and Wilcha is 22. They say they dreamed up the project because a high-school friend of Smith's was unhappy with the college he had chosen.

"The idea was, 'Let's buy Samuel a book,' but there was nothing, so we decided to write one," Wilcha recalls. "Our market research was one bookstore."

Later, Smith adds solicitously, "We did check 'Books in Print.' "

Smith's mother and stepfather, Washington-based writers Janet and John Wallach, helped the would-be authors find an agent, Nina Graybill, who liked their project. Graybill asked Smith and Wilcha for a three-page book proposal, and used it to find them a publisher, Avon Books.

She says the fact that John Wallach is foreign affairs editor for Hearst Newspapers had nothing to do with the contract from Avon, which also is a division of the Hearst Corp.

"There was never any association at all, it wasn't even an issue," Graybill says, adding that Hearst Newspapers and Avon are run separately. "John and Janet Wallach's name was never, never mentioned" to Avon.

The young writers -- who have been dating since shortly before they started the book -- use a romance metaphor throughout the guide, comparing the transfer process to breaking up with the old college, playing the field and then choosing a new partner.

"People seem to get very tied up in college, they get very hurt when it doesn't work out," Wilcha says. "So it really is like breaking up."

Smith and Wilcha did most of their writing during school vacations and the summer of 1989. They say they collaborated on every chapter and avoided writer's block by taking turns at the computer. "It was the best summer job we ever had," says Wilcha.

Adds Smith: "The minute you felt you couldn't write any more, you said, 'Okay, you read this.' And it just worked."

A fan of self-help and how-to books, Smith has a history of precocious entrepreneurship. He ran a catering business out of his parents' home in Chevy Chase at age 16, and landed a job as grill chef for Nathan's of Georgetown shortly after his 16th birthday by preparing lemon mousse for the owner.

"The owner tasted it," Smith recalls, "and he looked at me and said: 'I've been searching for five years for someone who could make lemon mousse. You're hired.' "

Wilcha says the prospect of writing an entire book intimidated her at first, but did not faze Smith. "One thing David always taught me was, 'Go with your ideas,' " she says. "As soon as we got the proposal down, we were both really excited that it was doable, that it would work."

The guide has its shortcomings: The index of transfer facts from more than 100 colleges at the back of the book, for example, is outdated and sometimes plain wrong. It lists George Stoner as dean, not director, of admissions at GWU, and names Andrea Sears as Georgetown's transfer coordinator when her actual title was admissions officer before leaving Georgetown in June, 1989.

But the book is useful because it provides real-life examples and down-to-earth suggestions that humanize the transfer process. It also offers checklists and timetables that can help transfer students meet deadlines and improve their chances for admission.

The University of Maryland's Christensen says such guidelines are invaluable for students entering the transfer process. "It is a real jungle," he says. "There are so many options and the counselors are so busy that its hard to find someone to sit down with you and explain things while you're still shopping" for schools.