If you are a football manager and have to playing a foreign team you knew nothing about in a few days time, what would you do?
You would research and find all the strengths and weaknesses of the team so when in competition you have a better chance of winning.
It is no different with online businesses. Research see what else is out there that is similar. Look at potential competition and keep notes on what you find.
Make the most of search engines to look for similar ideas, businesses or products and take notes on them. You will become a much stronger force against you competion if you know what they are up to and it will give you more ideas to play with.