Take some time to sit and keep an eye on what sells and what is not out of the topics you're interested in. Any market research data you can collect will be very useful for you later. You will probably see the sweet spots quite quickly - those one or two items that always seem to sell at a good price.
Step 2: See the competition.
Before you invest money, see what the other sellers in your category are up to and what their strategies. Pay special attention to any shortcomings of their auctions might have, because that is where you can move in and beat them at their own game.
Step 3: Find a product:
Getting a supplier for what it is you want to sell and see what are the best rates you can get. Do not be afraid to ring round quite a lot to get the best deal. If the eBay prices you've seen is greater than the supplier, then you are ready.
Do not throw thousands at your idea straight away - get started slowly, see what works and what does not, and learn as you go. Remember that it is very cheap to try even the craziest ideas on eBay, and who knows, maybe they just work!
Step 5: Test and repeat.
Keep trying different strategies until you find something that works, then do not be ashamed to keep doing so, again and again. The chances are that you? Just found a good niche.
Step 6: Develop a business plan:
A business need not be anything formal, just a few pages to describe the market opportunity you've spotted, your strategy, strengths and weaknesses in the plan and a short budget. It's more for you than for anyone else.
Step 7: Invest and expand:
This is the time to throw money at the problem. Buy inventory, and start spending more time on your business. Set a goal number of sales each week, increase it every time.
Step 8: Make it official:
Once you've made a couple of thousand dollars worth of sales, you should really register yourself as a business. Do not worry, it's not expensive or hard to do - a lawyer is the best person to help you through the process.
Step 9: Automate:
You will probably find that you write the same things over and over again in emails or item descriptions. It is time to give up on the manual method and turn to automated software that can create listings for you, and respond to completed auctions and payments with what you give to the message.
Step 10: Never give up:
Even when it looks like everything goes wrong, you should not stop trying until you succeed. If you keep working on it, then you will almost always find that you make a real breakthrough just when things are starting to look desperate.
When you come into the swing of things, you start thinking that you should leave your job and take up eBay selling part time. But it is not always as easy as that - there are all sorts of factors you should consider.