Use Spyfu tool you will atleast get an idea on what topic you will get maximum paid for a click. and then try to find sub niche of that topic because you can’t compete for broad keyword.
Suppose you want to build your website on health insurance then don’t target that keyword, target long tail keyword which has low competition and higher number of searches. So you target “health insurance quotes in ny”. I hope you understand what i am trying to tell. For more detail you can visit..