In most cases, there are full-time business brokers in midsized or larger metropolitan areas.
Brokers vary widely in their competency.
The better ones belong to professional valuation societies. Brokers always represent the seller, although there has been recent discussion in some quarters of buyers paying a fee to retain brokers as consultants. If you are selling a business, you can retain a broker by signing an agreement for the broker to represent you. Also, the broker contract should state that the broker will keep all of your information confidential. Any leads you have generated on your own should be written down as exceptions not subject to the broker commission.