"The 9/11 Commission Report: Final Report of the National Commission on Terrorist Attacks Upon the United States" goes on sale today in bookstores across the country. A paperback copy of the 500-plus page summary will cost $10. Because demand for the report appears to be substantial, some stores will be offering discounts.

Despite the fact that the report will be available on the commission's Web site, pre-publication sales have been hearty. On the eve of its release, the book was moving steadily up the bestseller lists on the Amazon and Barnes & Noble Web sites. Late yesterday afternoon it was No. 42 on Amazon and 66 on Barnes & Noble.

Bookstores have ordered more than 500,000 copies, says Louise Brockett, publicity director at W.W. Norton, which was selected by the commission to publish the authorized version. Some of those might be returned to the publisher by booksellers if they are not purchased in a timely fashion, but Norton is expecting robust sales: The first print run was 600,000.

"We've all worked very hard and diligently," Brockett says. "We really felt it was an honor as well as a responsibility to be involved in this."

Getting the books into bookstores so that sales can coincide with the commission's news conference today has been a challenge. Brockett says she cannot discuss the details of the bookmaking and delivery process. Several shops in the Washington area did not have the book as of yesterday afternoon.

The seven-store Olsson's Books & Records chain requested 300 copies from Norton. Alexis Akre, manager of the Rosslyn-Arlington branch, said she ordered 20 copies for her store, but by midafternoon the boxes had not appeared.

At Chapters downtown, co-owner Terri Merz prized open a United Parcel Service box, but found no 9/11 books. Politics & Prose ordered 200, co-owner Barbara Meade says. Fifteen customers signed up for the book ahead of time. She says she hopes the books arrive today.

Barnes & Noble spokeswoman Carolyn Brown says the books should go on sale around noon today in all the stores.

At least one other version of the public document is slated for publication. The Thomas Dunne imprint of St. Martin's Press is planning to produce its own copy of the report in early August. The paperback is listed on Amazon.com for $9.99. The commission's Web site is www.9-11commission.gov.