Ebay is an auction house for everyday computer users. It is VERY easy to use. You go through a step by step process to sign up and to list your first auction. I have sold a lot of my own personal items, as well as items I find on clearance that I know I can buy cheap and sell high. I also had a job with a company that would liquidate old merchandise on ebay, that was my job!
The downside: There are people out there that will bid and not pay, or people that will scam you in one way or another. Always bid with sellers that have a GOOD reputation (99% or higher). Never click through an email that says it is from ebay, go directly to ebay in your browser! If you have a bidder that doesn't pay you can go through a step by step process and get your listing and ending fees back. The fees for selling are low.