PageRank is directly propotional to the the quality of external website pages linking to you. It will help you a lot If you have some good PR Pages (PR 3+) linking to you. Important consideration here is I have written "external website pages" not websites. need to be very clear as all unique pages of websites hold their own PR value.What matters is the PR Value of the exact page linking to you.
You must go for firstly on-page SEO and becoz after determining his u will get an idea abt wht must u use making ranking on google.
Some factors include the number of outbound and inbound links. The more inbound links the better. Another thing is the number of do follow sites that are linked to your site.
The only way to get real PR is to build quality backlinks. It takes time & money, but it'll stick & give you a great site.
get the page. white hat seo technique best way to increase the page rank. ignore the black hat seo. some time gray hat seo best policy to increase the page rank. like gray hat seo can be defined as purchase the link from hire page rank website.
The PR's updating need many condition, such as the daily update for your site and the content and so on..
Find follow and no follow links. If a page is no follow it doesn't mean it is useless i term if back linking but as far as a high PR link, it may be severely watered down. Aim for follow pages with High PR.