It's better to have a room that's a little too small. A crowded room will make the meeting seem more successful than a large, half-empty room. Once you've got the date, place, topic, and speaker chosen, you're ready to publicize your meeting. Send fliers to the people on your sign-up sheets. Local TV stations are also worth checking for free announcements.
Newspapers often offer free services to publicize community group events.
Try both the established publications and the small, local papers. Once again, you may need to send a written notice a few weeks ahead of time. Call all the people to whom you've mailed a flier. If your speaker is willing, try to schedule talk shows or newspaper interviews while he or she is in town. Most of us are nervous on the day we're doing something special or new.