Keeping your web site fresh will prove to your visitors that you are learning more and changing with the times. If your site goes stale, you will be able to tell by the amount of visitors and visitor e-mails received dropping. The best way to prevent this is by constantly updating your information. You may wish to open up new sections or just add more info on a certain topic. Newsletter and contest may be a lot of work, but they keep visitors coming back again and again.
Newsletters are a good way of sharing information.
If you can't publish your own, try to have articles in newsletters as often as possible. Contest are a good way to attract visitors as well. A promotional tool that every webmaster should use because everyone can do it is swap related links. Not only are you getting targeted links to your site, but it is a good way to satisfy your visitors also. Some people may come to your site just because you can lead them to where they can go.