I've spent a lot of time discussing how you can use SEO to improve your website, but how are you supposed to know what areas need the most improvement? If you run your own website, you can use website analytics software to monitor all the traffic your site receives. This will help you identify the strengths and weaknesses of your site so that you can spend your time optimizing the right things.
This information will help you make important decisions about your website. For starters, you'll be able to see exactly how many people are coming to your site, and how they're getting there. If people reach your site from a search engine, you can see what they searched for.
You can also see which pages on your site people are leaving from. For example, if you have an online store, it's possible that lots of people start making a purchase but leave on a specific part of the checkout process. With that information, you can work to improve that particular page.
If you want to get started with analytics right away, Google Analytics is a very popular option (and it's free). Don't worry if you're having trouble figuring it out on your own because I'll write up some tutorials and reviews in the coming weeks.