Another keyword analysis/research tool from Google. Though this one is primarily intended for the Adwords Campaigns, still this gives us an idea what keywords are prominent in our websites and gives us the estimated traffic (US) thus allows us to know what to keywords to target even with our Organic Campaigns.
Here’s how the Google Search Based Keyword Tool works.
Keyword analysis is the first step in SEO, as well as when you are setting up a PPC campaign. There are a lot of tools to do this, both paid and free. I stick to the free ones for financial constraints 
.
How do we get the KEI? First step, is get the search volume of your keyword. I use Google Keyword Tool for this one. Next step is getting the number of competitors. Now we have the basic components for computing the KEI. KEI = Search Volume2 / # of competitors.
We get the KEI, we get the better performing keyword for both our organic search and PPC campaigns.
One of my favorite sources of search engine optimization (SEO) techniques is SEOmoz. The guides as well as the tools are pretty simple and easy to use. And the discussions at their blog section is awesome for beginners as well as for the seasoned SEO practitioners. Subjects ranges from keyword analysis to on-page optimization of a website.