I hope you have a list of keywords pertaining to your site! If you do not have list of keywords, do not worry, you will be able to generate one. I will refer you to a site that will generate a list of keywords from your content, already on your site or blog, after telling you how to find out if your keywords are popular.
Once you have your keyword list ready for reference, it is our task now to findout how popular your keywords are. Like how many people have googled them in the past month / year as well as now. So where do we go for that? Well not very far, just click on the link below which will lead you, to Google provided free keyword analysis tool.. Many people including yours truly use Google keyword analysis tools to evaluate their keywords.. Once you are at the site, you can either enter all your keywords, one per line or one by one. Either way once you are ready, click on “SEARCH”; Google adwords will provide you with Global, local search volume as well as competition information on all your keywords
Google Keyword Tool Sphere: Related Content