I had developed a site. While I Google search it, it comes up in 1st for 3 different search terms but it still hasn't got a page rank. Whats the meaning of this?
These are ways to increase page ranking in search engines like Google:
1) first of all, insert html meta tags for engine bots - this will advise search engines to properly index/follow/cache/etc. the page, i.e.:
<meta name="robots" content="index,follow,nocache" />
there is a specific meta that only Google recognizes, which is
<meta name="googlebot" ...
2) Google calculates the ranking based on links to your website from other websites. This is the true key to giving your website a good ranking - the more back-links you have - the better. Advertise your website by means of forum post signatures, etc.
The following is the wikipedia article on PageRank http://en.wikipedia.org/wiki/PageRank.
It does point out that the Google Bar page ranking is updated approximately 4 times a year, so often shows out of date values. It was last updated on 3 April 2010. The Google Bar page ranking is slightly different to the main search engines page rank.
PageRank isn't about where you appear on search results. It relates to how many external pages that are linking into your website. You can be first for many, many search terms and still have a PageRank of 1.
As well as Ruben's answer, it also takes time. Google only push out the page rank data every few months.