The NOWA House is having the kind of year that most Polish publishers can only dream about. In nine months, its managers say, it has edited and produced more than 30 separate titles, branched into audio and video recordings and sold out its entire production of 150,000 volumes.

The selection has been rich and the critics kind. There have been new novels by Polish authors, editions of respected scholarly journals and translations of Graham Greene and William Styron. One investigation of political upheavals in the city of Szczecin has been hailed as a major work of journalism.

The only problem, says one of NOWA's top managers, has been the inevitable arrests of a handful of the firm's 20 full-time employes and 200 part-time associates. For Poland's most prestigious independent publishing house also happens to be entirely illegal -- a clandestine company that edits, translates, typesets, prints and markets uncensored books despite the efforts of security forces.

"Every book we publish is a new victory for us," said the NOWA activist, who gave an extensive account of its activities during a recent interview on condition he not be named. "For police, there are just too many people involved. More than a publishing house, we are a kind of social movement."

If NOWA is a movement, then Poland's underground press has become a cultural explosion that has effectively ended the state's monopoly on information in a communist country. NOWA -- its Polish initials stand for "independent publishing organization" -- has kept alive an impassioned political debate, nurtured a nationwide network of antigovernment collaborators and helped Poland's official censors to become the most tolerant in the Soviet Bloc.

The dimensions of this independent expression far exceed the hand-to-hand underground publishing operations of dissidents in other East European countries. Poland boasts a veritable industry that opposition spokesmen say includes more than 800 publications, tens of thousands of workers and at least 1 million readers.

While such figures are hard to check, the numbers, variety and sophistication of clandestine publications readily available to a western reporter seem to support the extravagant claims. Products range from four-page weekly newspapers, 400-page novels and academic quarterlies to children's books with color illustrations and fine cloth bindings.

There are underground textbooks, encyclopedias and even periodical references that index and abstract clandestine titles. One such index recently listed 32 magazines dealing with East European affairs.

NOWA says its current projects include the publication of 60 volumes of archives from the 16-month legal existence of the trade union Solidarity, along with the release of cassettes of music and videocassettes of films banned by the government. Yet NOWA's well-tuned operation is just one of more than a dozen book publishing houses reported in the underground.

Even the state-controlled media has been drawn into the debates provoked by this outpouring. In the last month, for example, a book of remarkably revealing interviews with former Polish communist leaders, hauntingly entitled "They," has received extensive treatment in several official weeklies even though it was published by the underground house Future.

Such tacit acknowledgments of impact have helped confirm the position of independent publishing as the new center of Polish political resistance. "It is the most important factor in our situation. It is the first enemy of the government," said Stefan Bratkowski, a respected journalist and government critic.

"It is easy to organize a protest, but it is much more difficult to organize this cooperation of every day," said Bratkowski. "Protests can be ineffective. But these structures have the power to change the society."

Solidarity's leaders have increasingly emphasized the nurturing of independent debate and information over attempts to organize demonstrations and strikes. Most recently, the union clandestinely printed and issued a 165-page critique of Poland's social and economic conditions. "Through the underground press you can create fairly authentic public opinion," said spokesman Jan Onyszkiewicz.

Most of the printing industry is an outgrowth of Solidarity and the resources it amassed during its legal existence. Dozens of the underground newspapers distributed in factories and small towns began as legal Solidarity bulletins whose staff simply hid their equipment when the union was suppressed in 1981, changed the name of the paper, and continued publishing. Many magazines and books depend on a central network of distribution organized by Solidarity.

Moreover, Solidarity's organization has allowed much of the printing underground to depend on clandestine cooperation from workers in official print shops as well as substantial western supplies. The union's spokesmen like to describe how presses and ink can be fabricated from washing boards and detergents, but publishers acknowledge that they depend on western contacts for everything from large offset presses to stencils and staples.

Nevertheless, the industry clearly transcends the union's organization. NOWA was founded in 1977, three years before Solidarity, and its managers say their priorities are those of free expression, not political organization.

"We are trying to be an appendix to the official publishing, not a replacement for it," said the NOWA activist. "We want to judge only according to editorial quality. We try to publish good books, not just anticommunist tracts."

NOWA urges writers to publish officially if they can, and counts as triumphs the rare instances when its books have been reprinted by official houses. At the same time, it can offer a banned or censored writer a technical and commercial regimen that in many ways matches that of legal commercial publishers.

Take the case of translated foreign works, which for the NOWA activist are a particular source of pride. He said works recommended to the firm's editorial board are first referred to specialists who read them and prepare a critical review, in return for a fee from NOWA.

If the criticism is favorable, NOWA assigns the book to a professional translator who is paid an advance and a commission on delivery comparable to official rates. Once the translation is complete, the editorial board reads it and decides whether to go ahead with publishing.

Editions of up to 10,000 copies are printed, and the books usually carry prices of 400 to 800 zlotys, or $3 to $5. Sales of some volumes can thus amount to the equivalent of more than $50,000.

The NOWA source said Polish authors can earn enough to live on by writing exclusively for underground publishing houses, and the 20 technical employes of NOWA earn regular full-time salaries. All wages, he said, are assessed a 3 percent tax to fund assistance for employes who are arrested.

This technical and financial sophistication has been achieved with a highly decentralized, conspiratorial organization. Aside from its central editorial board, numbering fewer than 10 persons, NOWA is composed of four autonomous production groups that obtain their own supplies and other equipment and manage their own finances, the activist said.

The leaders of each group irregularly meet with members of the central board to receive manuscripts for printing and pass along royalties and suggestions for new projects. But even NOWA's top authorities do not know the identities of the production team members or how, when and where they work.

Police know the editorial leaders of NOWA because several of them publicly discussed their participation during the Solidarity era. But they have been able to crack production units only twice in the past year. "Police know who we are and what is done, but they don't know where and when," said the activist. "It's like the stories of Al Capone and other American gangsters -- they have never been able to catch us with the evidence."

All the same, the top underground publishers live haunted lives, working 16-hour days to cover both their official jobs and the duties of a publishing executive while evading police.

"Every day I'm happy to be in freedom, because every day I expect to be arrested," said the NOWA source. "But that's how it is in Poland. It's become a normal way to live here."