So i've been "promoting" (using the term loosely) my sites for the past month or so, and i was wondering what are the general requirements for each page rank level? as in, do i need to fullfill certain criteria in order to gain a level in page rank or is it calculated another way?
PageRank is calculated purely by links. Any page with PR has a little bit of 'PR juice' to pass on to any pages they link to. The higher the PR of the page, the more PR juice it has to pass on. So the more links you have from higher PR pages, the higher your own PR will go up. The PR juice of a page is split up to all the other pages that it links to. So if a page has 100 links on it, it won't pass as much PR as a page with the same PR but only 3 or 4 links on it. By the way, try to focus more on rankings and traffic. PageRank doesn't translate into rankings and is really only something for bragging rights.
I agree with Vanderstam. Focus your efforts on increasing your SERP. PR is only so you feel good about yourself but doesn't necessary mean more traffic.