As far as off-page SEO, you only need backlinks from various sources. I suggest you also look at social media marketing. Those Facebook Likes and Twitter Tweets and Re-Tweets of your webpage helps boost ranking. Hope that helps. Have a good day!
There are lots of activities in off page like, Directory submission, article submission, pdf submission, forum posting, classified submission, social bookmarking, press release submission, video submission, rss submission, etc.
Well, if I try to list all the activities of off-page optimization then it would be a list of more than 100 but what I would like to tell you you have to do it naturally with quality. Of course, you should have knowledge of all off-page activities so that you can build more natural links to your site and you would get higher ranking in Google search engine. Today, uniqueness is everything, try to create something unique for your website at regular basis and it would help for sure.
There are many seo off page activities like directory,article submission,forum posting,blog commenting,web 2.0 creation,social networking/bookmarking etc.
SMM, forum posting, article submission, submitting to directories, blog commenting, but most important everything you do should be original and high quality.
Of course, there are many off page activities, please make sure you are using only quality sites for link building purposes.