One great source for consumer returns is the Walmart Liquidation marketplace. Walmart sells lots of customer returned inventory on the site directly to any approved resellers. To get approved to purchase on the site only requires that you have a valid reseller's certificate.
They sell lots that range from a pallet or two up to full truckloads. Most lots contain products from a variety of categories. Occasionally, a lot will contain a single category. For example, there are frequently lots made up of nothing but TV's. Some of the categories common on the site include: furniture, bikes & rideons, home audio, outdoor furniture, and much more.
Every lot on the site is sold in an auction format and starts at $100 and sells to the highest bidder. There are no reserves. This is the purest form of a liquidation-minded seller. They are converting inventory into cash extremely efficiently.
The site is a great place for beginners to start but be careful to read the manifests very carefully paying particular attention to the 'reason for return' column. You can get a very good feel for the likely condition of every item from the code in this field. A great thing about the site is that you can trust that Walmart is making its best effort to represent the items accurately.