Targeting proper keywords or key phrases, groups of 2 to 5 keywords, is the way to market successfully with pay-per-click search engines and obtain high ranking in search engine indexes. It is a rather arduous task, but one that can yield massive returns in ranking, traffic, and sales if done correctly.

So where do I start?

Many free resources exist to research which keywords you should target. The two deciding factors are the number of searches performed on a particular keyword or key phrase, and the number of sites currently targeting these. It's nothing more than supply and demand.

Overture.com

The premiere pay-per-click search engine that previously supplied search results to several major search engines, is now on its own. Their free search tool can be found at: http://inventory.overture.com/d/searchinventory/suggestion/. Search results are displayed only for the previous month. This should be sufficient. The internet changes so quickly that what happened 6 months ago is not of much importance. What makes Overture's tool king in my view is that it provides hard numbers on how often a phrase was searched, allowing you to directly compare with the number of sites targeting each phrase.

Google Suggestion

Google has their own keyword suggestion tool. If you have an Adwords account then you are already familiar with this resource. This tool also provides related keyword information. It provides synonyms that might be used to target areas relatively untouched by others.

7Search.com

This PPC engine is steadily gaining in popularity. I have used it in the past to build my subscriber base and saw modest results. To use their keyword tool simply create a free account and log on. Then click on "Edit Bids" and go to "Keyword Suggestions".

Teoma.com

This search engine provides related search results and keyword suggestions in the results returned to the searcher. It can open up new avenues of keywords and phrases not thought about before. This resource can be found at http://teoma.com/.

Web Host Statistics

Unless your site is free (i.e. a free several page site through your ISP) you will most probably have site statistics. Have a look. My service is through StartLogic. The statistics are compiled through AWStats, which by the way is a free program for analyzing web site access. When I log into the server, I can view the statistics using AWStats. It also shows me which keywords and key phrases people are using to find my site. One great advantage I have found with this method is that you can come up with keyword ideas that you would have never thought about. Because people are finding you with these keywords the search engines must have you indexed.

Online Dictionary and Thesaurus

Well, you may have wanted to stay away from them in school, but, crack them open. These can provide you with additional ideas to then use in Overture, 7Search, etc..

WordTracker.com

This service is packed with many rich features to assist in keyword research. It starts at $6US per day. For $225US annually you are free to use it as much as needed. There is also a free version which does not have many of the extended features. I, however, recommend starting with this version. It will give you a taste of how it works.

Ranking.com

Use this resource to investigate how much traffic a site is receiving. You cannot research individual keywords and keyphrases.

As a final note put the required time into researching keywords and key phrases prior to submitting your site or starting a PPC campaign. Otherwise you are feeling around in the dark trying to find your niche. It is time expensive but not so for your wallet. This bodes well for online home businesses where time is usually not a concern.

For more information on keyword research I suggest checking out ClickZ.com. They offer a lot of advice on search engine marketing.