I, too was once where you are: just starting my eBay hobby (addiction, passion--whatever you want to call it). Many people who have successfully bought items on eBay now want to sell items too. Here is a guide to getting started based on my personal experiences.
1) Build your own positive feedback first. Once people know that you understand how eBay works, they will be more willing to buy an item from you. Hopefully, when you've bought items, you've paid quickly and left positive feedback (assuming, of course, you had a good experience). My advice is to have at least a "5" feedback before you sell. If you're waiting for feedback, leave positive feedback for your seller and then tell him or her that you'd appreciate their feedback because you're new.
2) Make sure you're ready to sell. Are you registered with PayPal? That's probably the first thing that buyers look for, so they can pay easily and quickly. Are you prepared with your mailing supplies (boxes, tape etc.)? Are you set up to mail your items?
3) Do your research. When you decide to sell your first item, see what similar items have sold for and how other sellers calculate shipping. I once saw a newbie seller list a popular book selling for $5 on average list it for $2 WITH A RESERVE PRICE! He didn't sell it--and was probably surprised that his listing fees were more than his listing price!
4) Sell something inexpensive first. Don't start with an antique vase or your old computer--start with a common item that buyers are familiar with, like a popular new book. Books are perfect--they sell quickly, they are easy to mail and buyers don't have to worry that they are purchasing a "fake" as with DVDs.
5) List at a LOW price to attract sellers. In general, prices will reach the market level of supply and demand. I've seen popular items listed at 99 cents that reach $100 in a matter of hours.
6) Once you sell your item and are paid, ship quickly. I try to email buyers and let them know when I've shipped. This way, they can look for their package. There's another bonus too: they often will say "Great communication" in their own feedback comments for you.
I hope this is helpful to you as you begin your exciting eBay career!