There is an organization called the National Association of Professional Organizers. It offers a variety of benefits, including liability insurance, medical discount cards (which are NOT insurance) and other things. You may want to start with them, as the insurers with which they deal are likely to be familiar with your trade and have tailored policies.
That said, you must be very careful that any insurance that you get is written by a licensed insurer; that is, the entity financially responsible for the payment of claims must be licensed by one or more state insurance departments. There is a sordid history of fraud in the insurance market-including health insurance-and often when insurance is sold to and through affinity groups.
You may also go to a licensed insurance broker to investigate coverage. A broker generally represents a variety of insurers, and is more likely to have a market for the insurance that you seek. In contrast, an "agent" usually represents only one or a couple of insurers and will have less of a choice of markets.
There are numerous companies that offer professional liability insurance to individuals. This, of course, depends on your individual location. Some great providers that I found are ISBA Mutual, Landy Insurance Agency, Insurance Plus and Lawyers Mutual Insurance.
Determining whether a company is good or not is subjective. One example of a good company, however, is NAPLIA, the North American Professional Liability Insurance Agency. They are a Better Business Bureau accredited agency with an A+ rating.
Rick Aldrup Insurance Agency in Wichita,KS offers liability insurance quotes for sports. It also offers quotes for auto liability etc
Healthcare Providers Service Organization offers professional liability insurance and risk management information to a wide array of healthcare and counseling professionals.
Most likely the coverage you need is called "Professional Liability Insurance". Just look in your local phone book or use an online search engine to search for the appropriate coverage type.
The Highpoint Insurance group offers commercial insurance. Their specific offers are Commercial Property, General Liability, Workers Comp, Commercial Auto, and Management Liability.
State Farm offers great rates on commercial liability insurance. FM Global is highly recommended also.
Allstate has a good plan. Check it out here www.allstate.com/auto-insurance/liability-coverage.aspx
Zurich Insurance offers and excellent small business insurance policy. This can protect you against things like product liability and workers compensation.
A person can find garage liability insurance through their business insurance provider. There are usually several insurance providers that specialize in small businesses.
Progressive, Gieco, Nationwide and State Farm offers public liability insurance. A public liability insurance broker may also help you in finding public liabitilty insurance. Prices may vary depending upon the agent and event.
The term 'excess' insurance is usually for liability coverage. An excess liability policy is also commonly referred to as an 'umbrella' policy because it offers additional coverage over other liability coverages. In the case of a subcontractors insurance, it would be a policy which would extend higher limits than the base policy on general liability and auto liability.