Well there are many ways and some are easier than others, but the one I'd like to mention is the long tail keyword method!
Think about when you yourself search for something online it is usually a good few words strung into a sentence to form a good foundation of search to find the information or products you want so think about what you would type in to your search box, think about your potential visitors and what they might type in.
While it is best when starting your website to target low rated keywords so you can dominate them and start to build up a reputable form of keyword networking on your sites, blog your keywords in the form of anchor text in your many links, cross link everything until you have a good strong network of valid high quality links, any links such as one way links, reciprical links or even if you can manage it three way linking.
Long tail keywords can be from 2 to 6 words or more, but try to research good keywords you can use as a quality phrase that you know people would search for, use the overture tool to research your keywords
Remember long tail keywords are good solid methods of placing your keywords around the internet, so have fun finding new places to add your links and try to vary your keywords and ads so that they don't get penalized as duplicate links or even content.