It is easy to check pagerank of main page manually. Just go http://www.prchecker.info and put your website url and click “Check PR”. But it’s really difficult to check PR of internal pages manually.
To check internal pagerank you can use a pagerank checker tools. It is good to check internal PR because you will understand how Google sees your pages and ranks it. It’s really possible to find PR of internal pages. If you find PR of an internal page, you can concentrate on that page more than other pages.
To check pagerank just go http://www.diagnosticoweb.com/internal