A Guide to Search Engine Optimization
BackLinks (links from other webpages)
A link on another webpage, especially if that webpage is on an established and regularly updated site, pointing towards to your site will ensure that search engines find your site. A single backlink will be sufficient, though creating a few backlinks gives search engines more chances to find your site. The best way to get such a link is by making a comment on a newly published article on a popular blog, as most blogs allow you to link back to your own site when making a comment.
Source: http://www.seomark.co.uk/submit-website-to-search-engines/#ixzz4WnI86PpC