If you're looking for the right keywords use googles get keyword ideas tool in the adwords section. Find the best keywords by looking at the amount of traffic a word gets in a month. Put each of the words with good traffic into google search with quotes around them to see how many other sites you have to compete with. next search the words without quotes to see what sites you'll be directly competing with for the first page. This site has a more detailed explanation about finding the right keywords and how to use them.
the first step, as described by redflea13 find keywords that will be a SEO campaign targets. Then the keyword optimization by providing high quality backlinks (according to the keywords)
First work on Baseline report-which provided plus and minus about the websites, then work on keyword research, then ON-Page and OFF-age Optimization..........