It's up to your group how to organize such a database. It can be used to make mailing lists, mailing labels, phone trees, even e-mail lists. Such data can be kept on paper, on three by five cards, on computers, or even in somebody's memory. It makes sense to exclude any sensitive information, but it is probably in your best interest to share any non-sensitive information with all of the members of your group. Even if you should someday find the perfect office or work-space, you will probably move around a lot in the short term.
Groups can fall apart because mail gets lost in the forwarding.
It makes sense to establish a permanent base of operations. Further, it makes sense both for security and empowering all members of your group to not have the mail sent to someone's house. You never know if that person might burn out or disappear. Ask to be listed in the Industrial Worker and on the Web as the local IWW contact for your area. You can contact the Industrial Worker elsewhere on this site.