You must first know what your website is about and search out other sites with the same type of content. Search for forums, blogs and articles with the same information, topics or content.
Register for the forums, sites and blogs you've found and put them in your favorites.
Start logging into these sites and setting up profiles, which happen to have spots for your personnel website. Set up a signiture on forums with your website in it.
Start creating threads and leaving comments on other threads and blogs with your website in your profile. If there wasnt a spot for a site then just start communicating with the other people on the site. In time you'll have your chance to share your site with them.
Look for sites where you can write articles or submit links.