Keyword Research and Analysis is the most important factor in SEO. It’s a valuable, and high return activities in the search marketing field. In keyword research you can predict shifts in demand, respond to changing market conditions. There are hundreds of free SEO resources available. Google Keyword Tools, webmaster tools, Google Analytics, Google insights, etc. are free and highly useful for SEO.
How to do Keyword research and Analysis in SEO : By SEO Zooms