One of the best ways to determine your site's theme as seen by google is to use the "site:" command in the query box. This query modifier will show all your site's pages indexed by google. Just like the regular results pages it will show titles of each page, but it will also show the description tag for each page as well. Regular result pages for search queries show the first sentence that uses that phrase instead.
So how do you use the "site:" command?
In google's search box type: site:www.yoursite.com. It will then bring up a results page that shows all your pages currently indexed by Google.
To analyze the information you have to simply look at all the titles and descriptions and see what are the most common keywords and ideas being used. You want to make sure your titles and descriptions are all unique. If there is a general theme that all your results are talking about this will help you become relevant for the keyword. Titles and descriptions are not all that matter though. Each listing that uses a term should be checked to make sure that page is using the terms on the page in it's body text as well. Titles and description tags are only as good as the content is. They mean nothing if the page doesn't talk about what the tags say it does. Learn about website content development.
Yahoo, MSN and other search engines use this command as well. So, check your relevancy in all of them.
