This article is from the eBay FAQ, by William B. Shaw firstname.lastname@example.org with numerous contributions by others.
Start small, selling relatively inexpensive items, that can be shipped
cheaply. Deliver them promptly, and pack them carefully. It's a whole lot
easier to sell a $5 to $10 item when you have no feedback than it is to sell
a $50 or $100 item. Count on not making too much if anything on that first
group of auctions. When you've built up a few positives, start selling more
People want to see a pattern of transacting business in an honorable
fashion. Starting small is the easiest way to establish a record of
honorable behavior. Admittedly, some people do the same thing to sell
nonexistent $2000 laptops, but if you're selling books and toys, starting
with the cheaper stuff first, and gradually moving into the higher priced
but still similar merchandise, people are less likely to automatically
assume you're a scammer.