I highly suggest you use Google Analytics or Woopra Analytics to monitor traffic coming into your website. With both services it is very easy to find out what keywords are bringing people to your site and this gives you the perfect opportunity to capitalize on what people are searching for. One of the most important things about SEO is delivering the right content to the people. Knowing what people want to know helps you achieve this.
Pillars and Supports
This concept has been around in various forms for a while now and many bloggers have talked about this idea. The idea is that you have your main pillar articles and then many support articles that all link back to the main pillar articles. A very simple concept that in my opinion works great for drawing traffic from search engines...