Register a business name with the secretary of state in the state that you intend to operate your dump truck business. You will want to set up a corporation (see Resources below).
Choose the type of corporation that you will need. There is no need to purchase the most expensive package, which will run you around $350, because all that you are paying extra for is for them to rush-deliver the paperwork.
Open a bank account once you get paperwork in the mail for your corporation. Choose a bank that works well with small business owners, and bring in the paperwork for your company and your personal identification.
Do some advertising. A good way to start is to get some business cards made up. Choose a design that fits the name of the business that you started. Also make up some flyers and put them in people's mailboxes to gain some local clientele.
Make sure that you get some advertising for your rig. A moving advertisement can generate a lot of revenue. Make sure that people can clearly read the logo and phone number on your truck. Also it is recommended that you purchase a trailer and a Bobcat to help with your business. More equipment will increase the amount of money that you can make with your business.