I always applaud anyone who decides to start their own business. In today’s economy it will become even more important for individual t have multiple income streams.
With that said, the advice I would give you would be do something that you are passionate about. Reason being is that you will be doing it 24/7. Secondly you need to find out if there is a market for your idea. If not for your initial idea maybe a variation on the initial idea.
There are several sites I always refer folks to when answering this question, and the first is www.sba.gov, this is a great resource because they offer a number of tools and tutorials I think are extremely helpful for someone considering a business. The second site I would recommend is My Own Business which is another site that is very ‘startup friendly’. I hope my answer has been helpful. I wish you great success.