Wilton Library’s annual rite of spring, its Gigantic Book Sale, gets underway Saturday, April 21, and continues through Tuesday, April 24.

The sale begins Saturday morning from 7 a.m. to 9 a.m., with a $15 early buyers admission fee. Beginning at 9 a.m., the sale opens with free admission for everyone for the remainder of the sale.

The sale on Saturday runs until 5 p.m., with the Rotary Club of Wilton providing hot dogs and sodas at lunchtime. Proceeds will benefit the library.

The fund-raiser continues on Sunday from noon to 5 p.m.; Monday from 10 a.m. to 5 p.m., when items are half-price; and Tuesday from 10 a.m. to 5 p.m., when purchases are $5 per bag, with bags supplied by the library.

Pat Gould, book sale co-chair, said the fund-raiser is an important event for the library.

“Every year, this effort brings in a significant part of the funds that need to be collected to put new resources — books, CDs, DVDs — on the shelves throughout the library in all departments,” Gould said.

The sale features more than 70,000 items sorted in more than 50 categories — mysteries, gardening, art books, travel, and science fiction; gently used, collectible, rare books, DVDs, CDs, and books on CD. This year’s sale includes many vinyl albums in pop, classical, holiday and Broadway music.

Janet Zuckerman, also a co-chair, said smart shoppers will attend. “This is such a wonderful event for smart shoppers — there are bargains to be had in every corner of the Book Cellar, where we have all our adult nonfiction, fiction, hardcover, trade paperbacks, CDs, DVDs, vinyl albums, biographies — choices that are wall to wall. And then there are all the children’s and teen items organized in the Brubeck Room, and the Collectors Corner in the gallery,” she said.

This year, organizers extended the hours for rare and collectible book purchases by creating the Collectors Corner. These special books will be accessible to all shoppers regardless of what days they visit; they may be purchased on the spot and taken home immediately — no waiting for auction results.

Hours also are extended for Tuesday, the final day of the sale. This year, the book sale will close at 5 p.m., giving savvy shoppers a few more hours to amass their goodies.

Elaine Tai-Lauria, executive director of Wilton Library, said she can’t thank her volunteers enough.

“This fund-raiser is near and dear to our hearts, and it is through their efforts, working throughout the year, that helps make this sale such a success. In these trying times of a tighter state budget and now given our town budget climate, this fund-raiser means more to us than ever,” she said. “We are appreciative of our volunteers, our book donations from the community, and our book-loving, bargain-conscious shoppers who make this effort the event that it is.”