Insurance for Tradespeople
My husband has started to work as a sub-contractor (carpenter). He's been told that he should buy carpenter insurance. I have no idea what kind of insurance it should be and where we can buy it.
What your husband needs is insurance on himself as a trades person. He will need both liability insurance (to cover his work and if anyone is harmed by his work) and he will likely need to cover himself in case of injury. A local trades group will likely be able to share more information about the kinds of insurance that are recommended for trades' people. Having said that, a small business insurance policy is likely your best bet.