The importance of accurate bookkeeping cannot be overemphasized in the online auction business. Learn how to keep very good books and maintain a solid paper trail of receipts, invoices, e-mails, payment notices, bank statements, and other items. If your business is successful and expands rapidly, you will have many transactions and many chances to make a mistake.

You will also encounter buyers who will erroneously or falsely claim that they did not receive something, or they will claim that they paid you when you know that they didn't. Your paper trail can silence them in a hurry and satisfy any investigators from the auction Web site. One very important part of bookkeeping is to do it daily or even several times a day, if needed. Don't let receipts pile up for a week or a month before recording them.

At the end of the year, you will thank yourself for being so diligent. Missing receipts can add up to a lot of wasted money. You may not be able to prove that you spent the amounts on business supplies, boxes, and shipping fees. Instead, you will have to report higher income and pay higher taxes as a result.