There are two type of back links in SEO Do-Follow and No- Follow. There are many techniques to create back links on the websites. Whenever Google crawler crawl the website they analyze the back links. IF website have the Do-follow back links then search engine follow the link. Google crawler always likes the do-follow links and passes for link juice. Here is lot of SEO techniques which gives us Do-Follow back links. Like blog commenting, Forum Posting, Directory Submission, Article Submission, Press Release, Social Bookmarking etc.
Before submission we should take a look on the website. If the website giving us DO-follow back link, we should submit in website. Including Do-follow website should have the high page rank. Because high page rank help us to achieve the website ranking in Search engine. This Do follow and high PR social bookmarking sites list will definitely help you to get better search engine ranking and traffic also. Here is Do follow social bookmarking sites list. Websites have also high PR.