Keywords are about knowing your customer. Who is your customer? Where are they from? What is their income? Why do they come to you? What are they interested in? What are their fears? Goals? What words do they use in their emails to you?
Who is your direct and indirect competition? Do they blog? What are they discussing on their blog? What makes you different?
Google Keyword tool: https://adwords.google.com/select/main?cmd=KeywordSandbox
Google Insight, so much fun!: http://www.google.com/insights/search
Keyword Spy, what are you doing? What is your competitor doing?: http://www.keywordspy.com/
