Here are some things to do every week once your site is up.
Check out the competition. Bookmark as many of their sites as you can and visit a few every week.
Check out other sites that your visitors like. You'll get lots of ideas as well as keep your finger on the pulse of the industry.
Check your status in a key catalog and re-register or correct your listing if necessary.
Review several pages of your site every week to make sure they're current. Add pages or modify what you've got as necessary.