Get your group to designate a spokesperson or press officer. Send out press releases about what you're doing to the local newspaper, radio, and TV. Follow up press releases with phone calls to make sure they've got it. When something major happens in your campaign, have someone ready to give an interview to the media.
Think of interesting angles on what you're doing and who your supporters are. Carrying out surveys, petitioning, demonstrations, handing out leaflets in the town, or imaginative publicity stunts can all be interesting news stories for your local press.
Seeds for Change have an excellent set of free resources on media work for campaign groups on their website.