Self-taught bookkeepers use a variety of courses, seminars, books, and other online resources to learn about bookkeeping and accounting. You can also learn how to use accounting software, like QuickBooks, which can teach you about the basics of bookkeeping as well as the technology used by many businesses.

"A bookkeeper records the financial transactions of an organization and takes care of day-to-day functions such as recording sales and invoices, paying bills and processing payroll," Stephens said. "Accountants take the financial data and analyze it to help organizations make financial decisions."

A bookkeeping side hustle offers incredible flexibility. It allows you to balance work with personal life. It also opens opportunities to work with a wide range of clients from different locations.