Hi. (first, sorry for my english, I hope you can follow me) Everywhere I read it's good to have backlinks from pages with a high PR. Ok, but there's one big question thats open on my side: Could someone please explain me how my page(s) benefit from having backlinks of sites with high domain PR, but low subpage ranking? Example: If I submit to a directory that has a high PR on the main page, lets say 5 or 6, but the directories category I submit to has low PR 1 or 0, does my site benefit? Other real example: dmoz,org has PR 8. I have two links there pointing to the same domain, but the pages where this domain is listed has PR 0. Do I benefit of having these two links on dmoz? Thanks to all.
Sure you do. High PR backlinks are more beneficial than low PR pages, but this doesn't mean it's bad to have low PR backlinks.
The PR passed (juice) from a page is the product of an equation that involves the PR of that page and the number of links on the page. The exact formula is not public knowledge and probably changes regularly. A PR3 page with just 2 links might pass on more juice to you than a PR7 with 200 links. You can get a high PR page using only links from low PR sites, you just need a lot of them and they should be from pages with very few links on them.
Like jkolarov said, all backlinks help, but the higher PR, the better. In situations where there is a high main page PR, sometimes that juice will get passed down once PR updates happen, especially if the site has been doing its work to get more inbound links. If you have the opportunity to get a free link on an appropriate site, you should take advantage of it. It can only help your ranking. Hope that was helpful.
A link from a related/relevant+family friendly site will be beneficial. High Pr links are good but low Pr links are not bad either and these will help !