Top, Shirley Sakey is honored with the first loan from Cambridge's new Main Library at 449 Broadway. Helping her at the Sunday opening is librarian Susan M. Flannery. Above, the first library card application is filled out by Ethan Kiczek as Amanda Pearson and Ethan Luke Pearson wait. (Photos: Marc Levy)

It took literally less than five minutes for the Main Library to be flooded today with eager uses, invading every nook and even just as swiftly logging on to public computers for Internet use. (Today’s crowd gets the benefit of live music as well until closing at 5 p.m.)

The first loan was complete even as doors opened — to applause — at 2 p.m. The honor, arranged ahead of time, went to Shirley Sakey, wife of the late Joseph Sakey, whose time as library director included the start of planning for this $90 million renovation. The first book out the doors of the new Main Library: “The Guernsey Literary and Potato Peel Pie Society,” by Mary Ann Shaffer and Annie Barrows, which Shirley Sakey had read about this morning in The Sunday Boston Globe.

“Now I can go home, sit down and read my book,” Shirley Sakey said.

The first library card application went to Amanda Pearson, Ethan Kiczek and their young son, Ethan Luke Pearson. Although they live across the street, Amanda Pearson said, “I haven’t been going [to a library] at all, so I’m excited by this opportunity. Maybe I can bring our new son and have people read to him.”

Even the first job request took place today, also within minutes of the doors opening. Elise O’Brien sat down with a librarian on the main floor to go over the possibilities — which, since the library’s staff was maintained even during the site’s closing for construction, didn’t look good.

O’Brien is also an avid reader, though, and excited by the library’s reopening; she lives near a branch library small enough she’s had to head to the grand Boston Public Library to satisfy her needs. Today, after finishing her interview, she was off to find a copy of “The Secret Garden.”

The Main Library, at 449 Broadway, opens again Monday for the start of its regular hours: Monday through Thursday 9 a.m. to 9 p.m.; Fridays and Saturdays from 9 a.m. to 5 p.m.; and Sundays from 1 to 5 p.m. For information, go to cambridgepubliclibrary.org or call (617) 349-4040.