Gov. Andrew M. Cuomo appeared before dozens of supporters at a Manhattan bookstore Wednesday to unveil his new memoir just weeks before the general election.

The release of "All Things Possible" comes as Cuomo faces Republican Westchester County Executive Rob Astorino in the Nov. 4 election.

"Writing the book is probably the hardest single project that I took on," Cuomo told about 200 people at the Barnes and Nobles in Union Square.

"It was more difficult, it was more heart-wrenching, it was more tedious . . . than I thought it would be," Cuomo said. He added that it was one of his most "rewarding" experiences.

The book, which went on sale Tuesday, delves into Cuomo's personal and political life, including his failed bid in 2002 to secure the Democratic nomination for governor and his 2005 divorce from Kerry Kennedy.

The book also touches upon Cuomo's relationship with his father, former Gov. Mario Cuomo.

"I don't believe my father's story was ever given a just accounting," Cuomo said.

Outside the bookstore, about 100 protesters called on Cuomo to ban hydraulic-fracturing for natural gas in the state -- a practice that is now under moratorium.

Meanwhile, two aides with Astorino's campaign handed out fliers before the event announcing the campaign would give $1,000 to the first person at the book signing to get Cuomo to answer five questions on video related to the governor's disbanding of the Moreland Commission on public corruption. The state panel, which Cuomo convened and then abruptly shut down, is the focus of a probe by U.S. Attorney Preet Bharara.

"At a book signing, Mr. Cuomo is making himself available to savvy, everyday New Yorkers -- I just know one of them can make him talk," Astorino said in a news release. "All things are possible."

The State Democratic Party offered $2,000 to any New Yorker who asks Astorino on video why he has not released five years worth of his tax returns. Astorino, who last month released his most recent tax return, has said his financial disclosure forms cover his past five years.

Also Wednesday, Astorino was endorsed by former Republican New Jersey Gov. Christine Todd Whitman. Whitman said in a letter to supporters that Astorino has a "proven record as a tax cutter and budget reformer."