There is no business in the world that is totally self-sufficient and does not depend on other businesses to create leverage, discuss issues and problems, and learn from one another. One of the most missed sources of leads, information, and advice is your peers.
You should go to business and chamber events (and any other event, for that matter, that relates to the improvement or advancement of your business) where you can meet with other businesses in your community. This is a rich source of information and you'd be surprised what you will find out.
However, as with any organization or group you join, you will only get out of it what you put in. If you only go to one or two meetings a year, don't expect much. Instead, become involved--better yet become a leader. Volunteer for events and functions. Join a committee; become its chairperson.