Last week we started a new wikiproject at pl.wiki for coordination of a large project devoted to librarians, libraries, books, bibliology and related topics. During wikiworkshops I gathered a list of email addresses of people interested in taking part in the project, later this year we will hold additional workshops, in January we plan an editathon, there's a list of red links in the making - all in all the project is in full swing. I guess a public mailing list will be the easiest way to contact the participants.
The name most consistent would be wikipedia-pl-bibliotekarze@lists.wikimedia.org, as it's intended for librarians active on Polish Wikipedia (bibliotekarze means librarians in Polish).
The initial list administrator's address is krzysztof.machocki@wikimedia.pl (my official chapter's address), we'll add additional admins if need be. Secondary email address is j.potega@gmail.com (the group's leader on behalf of the Polish Librarians Association).