To start a data entry business, reach out to past clients for new projects and opportunities. Network with friends and acquaintances for referrals. Use platforms like Upwork, Mechanical Turk, and Virtual Vocations to find data entry gigs. Utilize social media, your local Chamber of Commerce, and cold emailing or calling to find clients online. Understand your target market, identify costs and financing, create a business plan, and develop a marketing strategy.