"They're all compulsive people," said Marcia Carter, Class of '62, half-seriously, gesturing at the hundreds of bibliophiles who showed up for the opening of the five-day, 28th annual Vassar College book sale.

First in line was Shannon Ferguson, who arrived at 8:30 p.m. Wednesday and spent the night sleeping on the sidewalk in front of the office building at 1114 21st St. NW. where the sale is held.

Ferguson, who apparently is not a professional collector or dealer - though the sale attracts many - has tried to be first for the past 10 years. He had about 299 companions in line by the time the doors opened at 10 a.m., according to Barbara Waterfall ('65), a publicity worker.

The sale, which each year draws several thousand people - many of them regulars - is apparently the oldest and largest of the local college book sales. Volunteer alumni work throughout the year to collect and sort the 100,000 books.

According to Sally Roman, ('65), most of the books come from bequests or estates but, she notes, "They're donated by all kinds of people from all over the area."

Last year the sale raised about $36,000, which provides 20 scholarships to Vassar-bound Washington-area students.

One anthropologist who's been coming to the sale for 15 years phoned Marcia Carter, who also owns Booked Up, from Mexico City to say he was upset he wouldn't be able to come this year because he's on a dig.

Other hardcore regulars come from New York and California to snap up books on subjects ranging from medicine and economics to biography, Americana and military history. Big draws are the tables of paperbacks (20 cents each or three for 50 cents) and the rare books. But all sections are peopled by both the painstaking browsers who examine each book and the more kinetic who quickly look through the offerings on one table and move on to the next.

Among the more serious amateur collectors was Peter Holden, who arrived at 10:15 a.m. ("A little late") with his friend Terri Miller. Miller stood guard over two huge, nearly full canvas mail bags borrowed from their office while Holden happily searched for issues of "National Geographic" (he already owns 1,000), biographies, books on chess - everything but fiction."

"I made a big mistake the first time I came six years ago," he said. "I brought 50 paper bags which all ripped. Today is the best day for the new stuffI'll be back Saturday when I can spend lots of time and Monday night when everything is reduced."

Holden's prize acquisition from his years at the sale is a leather-bound 1927 Aubrey Beardsley first edition of "Salome." It cost 40 cents. Holden positively gloated as he recalled, "It was just lying on the table, not even in the rare book section."

Offerings in the rare book section yesterday included a 10-volume leather-bound collection of the writings of Victor Hugo for $9.50 with a Jouette Shouse bookplate, and a 12-volume edition of O. Henry priced at $8.50.

Other finds: J. Edgar Hoover's "Masters of Deceit" for 60 cents; a two-volume set published in 1925 entitiled "Yale in the World War" for $8; a 35-cent paperback, "Can Telepathy Penetrate the Iron Curtain?"; the 1972 Internal Revenue Code for 40 cents plus "Of Mauve Gloves and Madmen, Clutter and Vine," for $3.50 which retails for $8.95.

Tonight's sale culminates in a silent auction which features three rare books, including a 1541 Gutenberg Bible.

The most aptly named book was neither rare nor esoteric. It was a 20-cent paperback entitled "Hooked On Books."