If you don’t choose a business structure like a corporation or LLC, you’ll automatically be considered a sole proprietor (or partnership) by the IRS. However, operating as a sole proprietor, your personal assets are at risk. If your company is ever sued, the court can seize your personal assets if your business doesn’t have enough to cover its debts. Both the corporation and LLC separate you and your assets from the business, and provide other tax benefits.
A checklist is a type of job aid used to reduce failure by compensating for potential limits of human memory and attention. It helps to ensure consistency and completeness in carrying out a task. A basic example is the "to do list". A more advanced checklist would be a schedule, which lays out tasks to be done according to time of day or other factors. A primary task in checklist is documentation of the task and auditing against the documentation.