Adding new features to existing website and optimising for traffic flow and advertising

I am the owner of a non-profit site which features opinion pieces on Jewish history and politics. The site is operational and I now wish to add several features to the site such as a discussion board page integrated with facebook, a polls section where I can upload a daily or weekly poll topic and readers can vote and several other such features like dividing articles into sections, improving the email subscriptions process and including a photo gallery section. I also want to generally improve connectivity with facebook and social media and also ensure that the site is compatible with smartphones (android/iphone). I am also now looking to commercialise the site and want to replace some of the links on the homepage with ads, requests for donations and options for advertising packages on the site such as Amazon. I also want to drive traffic to the site so want to optimise the site for search engine purposes and find other ways of getting as many hits as possible.