Purchasing links would do more harm than good to your website.
Just concentrate on doing the basic SEO of your website, and do it yourself. No one knows your website more than you. So, search for basic SEO tutorials on Internet, and go ahead with it.
Good luck
Google +1 button is a great amalgamation of Social Media and SEO. It is just like a Facebook Like button, with a hint of SEO.
The more +1 your website or webpage gets, the better its ranking on Google becomes. So, you must place a google +1 button on your website.
Social Networking has not been very successful for me. May be because I don't have a huge friend list. Twitter brings more traffic on my blog than Facebook.
Moreover, I find Social Bookmarking more effective than Social Networking.
Not at all. According to the latest Google Panda Update, if your website contains duplicate content, Google will place it at the bottom of Search Engine rankings. It can also ban your website (but that rarely happens)..