Well Pete,I have been a seller and buyer on eBay for 8 years now and this is what I think will make your eBay experience a happy one.
1.Be honest in your descriptions.
2.Be prompt in answering emails.
3.Be fair in your postal charges.
4.Be patient with your buyers.
5.Accept payment from anyone and anywhere in the world(as long as they are pay you in US currency of course).
6.Offer items at a reasonable starting bid.
7.Give feedback after every transaction.
8.DO NOT USE the word "RARE" in your description...unless of course there are less than 10 examples known in the universe.
9.Be concise and accurate in your description heading.
10:Don't panic if you do not have a bid after the first 6 days of a 7 day auction as most bidding takes place in the last few hours or even minutes.
11.Do not pull end an auction early if someone makes you an early offer,as you will almost always get more for the item if you "let it ride."
12.When payment arrives try to always notify the buyer and also let them know that their item is one the way.
I am sure there are a few more things to consider but you will learn them as you go.
GOOD LUCK!