Look up the sites that are providing links to the websites of your competitors. This is a good way to start your SEO link building efforts, since websites that link to your competitors are likely to be interested in linking to your site as well. However, before implementing this strategy, make sure that your website is as good as your competitor's.
There are many SEO link building tools that can help you check your competitors' SEO links. SEOBook Back Link Analyzer provides comprehensive backlink information. It's free, but only runs on Windows. There's also the impressive (paid) SEO SpyGlass, which runs on Mac, Linux and Windows.
