For multiple page websites, does increasing the pagerank on one page increase...

[brown_h0rnet]

...your other pages rank? Or do you have to do SEO (backlinking and so forth) for each individual page?

[Civic SEO]

Each web page has it's own unique Pagerank, the way Pagerank is gained is by backlinks to your web pages from off-site backlinks. Yes, internal linking does distribute Pagerank, the issue is it divided up just the same as with outbound links, so if you have 5 internal links and 5 out bound links on one web page your passing on in theory only 1\10 of the possible value you can.Now, if Pagerank is divided up different via internal links and out bound links is something only the Google engineers would know and keep secret to prevent abuse. You best bet is to build backlinks to all your web pages, using proper anchor text to help your SERPs as well.