From the fantastic book "Jump Start Your Book Sales" by Marilyn & Tom Ross!
"The 7 Habits of Highly Sucessful Publishers" (summarized - go pick up a copy!):
1. - Own your niche. Decide what major subject area you'll publish in and concentrate on it exclusively.
2. - Select highly promotable authors and treat them as your partners. Their passion & energy make them the book's best salesperson.
3. - Cultivate word-of-mouth.
4. - Make it easy. To get people to do what you want, make it easy for them to cooperate.
5. - Ask for what you want.
6. - Apply the 80/20 rule. You'll get 80% of your PR results (or orders) from 20% of your efforts (or customers.)
7. - Follow up follow up, FOLLOW UP. ...the squeaky wheel gets the grease.