Ok, you've worked your way into some positive feedback, bought a few useless items and ebooks and you're ready to go. Those transactions are not only to get yourself some positive feedback, but also getting yourself acquainted with the Ebay universe. Nothing helps you more in learning than actually doing. You'll get to see what type of people you might deal with. One thing you cannot forget is to keep your customers informed.
Before you get customers, you have to sell something. Let's do that, now log in and go to the "SELL" section of Ebay and start by choosing what type of sale you want to do. I never bother with anything else but live auction. No reserve, no buy it now, just a live raw auction with a low starting price, $0.99. It will get the ball rolling since you low ball everybody, except for the ones selling their stuff at a penny, but those guys usually charge $30 or more for shipping (That's the BIG secret of penny auctions by the way, just saved you some bucks on an ebook!).
Choose the category in which you will sell your thingamagy, because you DID read this blog and you DID do your research...right? Ok, now list it at the price you want and write a decent description. Always let people know what is defective with your doodad if there is anything wrong with it. Take a good picture, people want to see. Even if what you are selling is very rare and in high demand, you will never get top price if your picture is crap. Invest in a decent digital camera that can do macro shots, it will pay for itself.
Putting a picture in a the Gallery for the extra $0.35 is worth it most of the time. When doing a search people will notice your beautiful picture and will just want to go see your listing and they will ignore the other guy who just wrote some long small text, 'cause people don't like to read and they want it fast and now.
Put as much stuff as you can in the title, write in CAPS, it's free. List your stuff and good luck.