There are so many ways to get back links like directory submission, press release submission, article submission. blogging, forum posting , yahoo answering, to give links on social media sites etc....
You can get links for your website from various Forums blogs social bookmarking article submission press release Groups communities classifieds comments link exchange program (less chances of success)
There are so many ways to get good back links for you site. But as far as my view is concerned, I prefer to exchange links with relevant good ranked site. Because it does boast your search engine ranking!
submit to quality web directories to boost PR and link exchange with related site to boost quality traffics.
You can get links via article submission. Write few articles, and then submit them to online article directories.
Social bookmarking, directeries, and you can post in online forums. A really good ones to post in is http://www.sitsellforums.com under the "Show off your site" section. You may also post in signatures on different forums, such as digital point