I am wondering if I have a website or blog and have links to high PR websites, do those links out to other sites affect my PR or SERP at all? I would think of an example would be my site is a PR3 and I have 4 links leading to different high-PR sites (Digg, Digital Point, Delicious, and Reddit), now would those links do anything for my website?
Outbound links are also important, and according to my experience, linking to some quality sites increase your credibility.
page Rank is a big concept , link-building helps pagerank to about 90%, apart from back-links you need to have unique content, high number of visitors to get a good page-rank. Digg,Reddit,delicious have no-follow tags ,they wouldn't help you or demote you. since they are bookmarking sites and they dont have any limitations.even a blog post written by a 3 year old can be book marked. try to write A-Z ina apost and bookmark,doesn't make any sense to you and google.although try to get some back-links from twitter