Do follow social bookmarking sites are critical to not only syndicate your website across the web, but get credit for the quality backlinks from search engines such as Google, Yahoo, and Bing. Most social bookmarking sites are do follow, or send quality social signals such as Twitter, even though it's technically no follow. Rather than updating my personal list each month I decided to go with Bookmarking Beast http://www.bookmarkingbeast.com as they submit to all the do follow, and some no follow social bookmarking sites which has given us a great boost in the search results and we couldn't be happier.