Either set up your program to print labels or make one set of labels and make at least 12 copies onto more labels. For every press release, make a flyer that just gives the 5W information. Also post the flyers when you mail the press releases. Always include full contact information for more information. If you can send a photo along with your release, you might be far ahead of the game.
Snapshots are just fine.
Just don't expect to get it back. Call on every contact and find the person behind the job. Take along a little basket of home-grown preserves or something else nice. It isn't a bribe, it's just an introduction. Be rememberable in a good way.