For the first time in five years, the publishing world returns this week to Los Angeles. The mighty BookExpo is bigger and bolder than ever. You’ll find digital innovations and green-come-lately initiatives galore, and everyone from print-on-demand authors to A-list celebs touting new books. This spring, however, you also may detect a jittery edge to the high-powered mingling and martini parties. Hillel Italie of the Associated Press offers an overview:

Around 30,000 publishers, authors, agents, booksellers and librarians are expected in Los Angeles, at a time when the industry faces flat sales and possibly radical change. Random House, coming off a disappointing 2007, is switching CEOs. The Borders Group superstore chain may go up for sale, possibly to rival Barnes & Noble Inc., which itself has had a difficult year.

“I would anticipate a somewhat more subdued mood than in past years, playing out against a continuous thrum of chatter about shake-ups and shakeouts and impending changes bad and good,” says Steve Ross, publisher of the Collins division of HarperCollins. “I also expect the usual jockeying for possession of `The Next Big Book,’ since there are no clear candidates.”

On the red carpet: USA Today, meanwhile, offers a roundup of BEA parties feting Prince, Ted Turner, Barbara Walters, chef Gordon Ramsay and other celebrity authors. The New York Observer compiles another party guide here.

On the bus: City Lights Publishers teams up with Esotouric for a Saturday night romp through Charles Bukowski’s LA. Note to BookExpo attendees: show your badge when boarding to receive a pre-release copy of City Lights’ Bukowski anthology, Portions from a Wine-Stained Notebook: Uncollected Stories and Essays, 1944 -1990. (Read an excerpt here.)

On the beat: We’ll be heading to the Los Angeles Convention Center and filing occasional BEA dispatches through the weekend.