Page Rank (PR) is determined by number of incoming and outgoing links to a website. Google uses certain algorithm to determine PageRank of a web page. It is periodically updated. My blog have not yet get ranked by Google. That is why link building is important. Your site must include pages that contain links to other sites that have good page Ranks. Simultaneously other sites must contain links pointing your site. This is the secret of PageRank.
I have given a tool to check your web sites page rank. courtesy: www.prchecker.info
You can find the tool at the bottom.