I sold on ebay for over 10 years so I'll put my two cents in.
First of all, you are at a disadvantage as a new seller. Your items will not show up as well in the searches unless you have something very, very unique. This is especially true if your items vary in category.
For this reason alone, you face the risk of starting something out cheaper than you ought to and getting on one sniped bid at the end. Think about Buy it Now to build up some credibility and gain feedback. Make sure you offer great customer service and fast shipping, communication etc.
Look around at what other people are selling their items for and stay close to that. Once you keep good feedback and list lots of products you can think about starting your items off lower and watching them go up. If you do put a reserve, make it reasonable, and let everyone know what it is. No one wants hidden reserves and to waste their time bidding on something they can't afford.
