1. SEM tips from Banc Media

2.  Google suggest  AdWords Keyword Tool  Search Metrics  Soovle  Bing Keyword Tool

3. This is the best starting place for any keyword research. Just begin typing your keywords and see what related terms Google suggests!

4. Enter your keywords and see their estimated search volumes according to Google. Look further down the page for related keyword suggestions

5. One of the more powerful keyword research services. It requires a paid login. See which keywords your competitors are ranking for and how much traffic they deliver.

6. Similar to Google Suggest but data from multiple sources. Begin typing your keyword and look at suggestions from the web…

7. Save keywords to a list or copy/paste them

8. Very similar to the Google AdWords Keyword Tool. Simply enter a keyword and see search volumes, trends and related keyword suggestions. Invaluable data and perhaps more of a reliable indicator than Google’s.