Write letters to the editor expressing your concerns. Be able and willing to answer media questions raised by your comments at public hearings. Ask to be allowed to appear to discuss major library issues. Some local radio stations will do public service announcements or allow one-minute editorials on a topic of general public interest. Take advantage of all these media opportunities, and others, to alert the public about the library's situation and what people can do to help.
Timing is an important factor.
For example, media coverage can be especially effective during the budgeting process as elected officials make their funding decisions. Sponsor events that highlight the library's importance to the community. Work with your library staff to identify event opportunities to highlight the value of the services the library provides to the community. Sponsor an open house to show the public what has been achieved up to now and what is planned for the future. By publicizing major library events, you're demonstrating why the library is a valuable community institution.