Your site also has to be set up correctly, for google to recognize it. Example heading tags, alt tags in photos
Don't do too much social bookmarking it will get you penalized. Just do about 3 or 4 a day. Article directories are alright - they were just hit by Panda but... - they are one of the best options for getting free back links. Just make sure you submit to good, high PR article directories. and don't spin one article, submit a unique one to each article directory.
Page rank given by the google depends on the how many one way links you have and from where your links coming from. edu back links are very good with respect to google . Google visits edu site regularly and if you have back links from those sites, your site will be indexed faster and can get good rank to your keywords.
i think the more you work that soon you will get the fruit so try to blog comments whether do follow are do not follow google will read it and forums comments directory submission social bookmarking and etc,.