No Follow links do not pass any PR, that was the main point of creating the attribute in the first place. Google wanted to try and curb the spamming of sites, so they stopped passing PR to sites that were only there for a link. In it's current state, Page Rank is equally distributed through the number of links on a page, so if you have 5 links and they all pass rank, that's great, each page you link to will receive 1/5th of the pr from that page. You can no longer sculpt your PR though, so if you have 5 links and 2 are no follow, then the 3 that you're allowing to be followed only get 1/5th of the PR available, while the 2 pages that are no follow get nothing, the PR that was alloted to those links goes off into nothing.