Keywords are such little things – typically one- to three-word phrases – but their importance cannot be over-emphasized when it comes to search engine optimization. In fact, choosing the right or wrong keywords could be the difference between your site being found by the search engines or remaining forever in search engine oblivion.

The keyword selection process is not a short task. It takes an intimate knowledge of your market, detailed research into your competitors’ keywords and lengthy analysis of the results that you find. The following tools will help you narrow down your list of keywords so that you come up with the ones that are best suited for your business – and get your site found by the search engines.

Wordtracker – Arguably the industry standard, this keyword tool allows you to determine how many times a specific term is searched on, how many competing sites use those keywords and also suggests related terms that you might not have considered. The service ranges in price from $7.32 per day to $244.02 per year. There is a free trial available.

Overture – This free tool from Overture (a pay-per-click advertising network) allows you to search your potential keywords and see how many searches are done on those keywords per month. It also lists longer search phrases that include your keyword, along with their monthly counts. One thing to note is that Overture does not differentiate between singular and plural forms of the search terms.

Log files – Many times this tool is overlooked, but the log files for your site have a rich collection of data that you should examine to find out how your customers are reaching your site. If you check your keyword referral logs, you’ll be able to determine what keywords are currently working to send customers your way, and the logs may very well present you with additional keywords for which you have not yet considered optimizing.