Increase Site PR

Just joined but I have been in the industry for about 15 years. New to SEO/SMO though and I’m trying to build my knowledge before making any mistakes…

I want to increase my PageRank and feel that the best way to do this is through really good off-site link building and active social media. I have made all of the needed changes to my site (on-page).

Here’s my question:
Can you buy high PR links? Or is this considered ‘cheating’ by Google? I want my search results to appear and to actually be organic, but if I can give my site a boost while I proceed with the 12 month SEO campaign it would help.