Need some Keyword ideas?. Google provides an excellent tool for this, the Google Adwords Keyword Tool. It's the same tool that advertisers use to decide which keywords to bid on.

Whey you search for a phrase they provide a whole list of Additional keywords to consider and provide some valuable stats, like the Approx Avg Search Volume and the Competition it has on Adwords. Some people suggest that it's like Adwords in reverse :)....

I personally like a cool feature that it has where you can easily create a list and export it to a text file or CSV for future use.