My husband just started a non-profit business and will be taking donations. Could I be personally liable if something goes wrong?

Spouses are generally not liable for each other's obligations except for what are known as "necessaries", i.e. things which are absoluitely necessary for the other spouse's well being, such as emergency surgery.  If your husband falls off the bike and needs emergency medical treatment for which he can't pay, you could be liable for it.  Of course, you could be liable in such a scenario without regard to any business.  Other than that sort of thing, I'm having a hard time picturing any scenario where you would be liable for some problem with your husband's business in which you are not involved.