Regarding researching the products, a very useful tool to use is terapeak, not free, but quite valuable for the serious ebayer. Something more simple is to use ebay listings themselves.
Take a look at current listings, check the prices, compare auctions to BIN options, and then check completed listings to see how well the sales have been performing in the recent past.
Speedy delivery time is always an excellent thing to offer, great customer service is a good way to get great feedback, and create return business.
I myself offer same day despatch for orders with payment confirmation received before 11.30am weekdays. Now some might think that 24 hours would be the same, but it creates a lot of local sales for me because someone living in Brisbane paying for their game before 11.30am, means they should have that game the nest day (given that Aust Post do their job)
That gets my nose in front of another seller offering 24 hours, because the chances are that they won't ship till the next day, and that's an extra day the customer is waiting.
Might not sound like much, but it's all those little things that you can sharpen up to get your nose in front of the pack!
There are quite a few triggers that you can pull to create a sale, even though you are limited to less when dealing with on line sales. I've only just started my new ebay venture, but I have promised to show a few members some marketing tricks that we have implemented already.
What I may just do is drop some links in a thread over the next few days, point out what we have done, how we have done it, and why we have done it, then others may well be able to take some tips and make them work on their own accounts.
So keep an eye out for that, I think you may well find an idea or two there that will be of interest to you.