My vote goes to google adwords keyword tool and your common sense. Here's the strategy: 1. start with making a long list of keywords people might use to find your website. Try to forget that you're doing it with seo in mind - imagine you're a user. 2. ask other people what keywords they might use. 3. then go to google adwords keyword tool to check your keywords. remember to use exact match - it's important to get accurate results. 4. finalize your list: choose words with sufficient number of searches (up to 4k is worth going after for newbie SEOs) and low/medium competition.