Local Chamber of commerce and SBA is a must IMHO.. especially if you are in certain areas. You'd be surprised at the connections of other businesses in networking. One of my clients actually owns the local golf course here, found him through our chamber e-group a few years ago when just discussing flyers, I had no idea he was a physician.
This is a best kept secret, and a bit morbid but it works.. scan local obituaries with terms Death, office manager, etc. Don't laugh.. I've seen people get clients.