Shopping on Ebay can be good fun and extremely rewarding experience. You can find items here that you may not be able to find elsewhere. If you are carefull.
know what you are looking for, try searching using different descriptive words for the same item. Take your time, read item descriptions carefully ( for example if something is described as genuine copy) then it is not the original it is a copy. If in doubt ask seller a question. Allways check postage prices and payment options. Allways try to leave yourself plenty of time. If bidding in an auction then set yourself a limit of the maximum you want to go to and stick to it. There will be other auctions.
Allways have a look at a sellers feedback scores and also there feedback comments as it is usuall for someone to have a few negatives if they sell a lot, this is normally down to postage problems. Looking at there feedback will tell you this.
If you have bought an item and it hasnt come as quick as you expected then dont panic just email seller and ask nicely if they can let you know when item was posted, nine times out of ten it will be royal mail at fault. Allways communicate with your seller politely they are normally happy to help. Only give negative feedback if the seller really deserves it.
Most importantly do not ever give any of your financial details to anyone. I personaly use Paypal as this is very simple method of paying without giving out any financial information.