How you file your business's taxes will depend on the entity type you register. If you are a sole proprietor or a single-owner LLC, you can file a Schedule C when you file your personal taxes each year. A corporation also files an annual tax return. If you will file a Schedule C with your personal taxes, and your business makes a profit, you may need to pay estimated taxes each quarter. You can find information about estimated taxes and download the required form on the IRS web site. If you will have employees, then you will need to withhold taxes from your employees' income and remit them to your state and the IRS each quarter. You will also need to withhold Social Security and Medicare contributions. To do that, you will need to set up accounts with the IRS and your state department of labor.