How to find out the most expensive keywords using Google Keyword tool?

I wouldn't know and fortunately, you don't need to most expensive keywords to get rich. Low paying keywords with a lot of traffic will do just as well and they're most likely easier to rank for.

The easiest way is to pick off your keywords category by category and sort by descending avg. CPC. Health, finance/credit and similar topics tend to have high CPCs if you want somewhere to start.

However, as simeonvisser said above, you are better off trying to find the related keywords people aren't bidding so much for and aim for more niche content. Hope that helps.

I guess the number of searches performed with that keywords appears just to right side of them.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.