An excellent way to gain in-bound links and page rank is to submit your site to
link directories. Directories catalogue links so that users can have easy
access to them and they also publish these links on the web so that they can be
found and indexed by search engines. These are excellent for getting your site
noticed.
Another way is to find websites with the same or similar niche as yours and providing them a link to your website, normally in exchange for a link from theirs. You place the link to their site on your link page and they reciprocate.