what is exacly rel=nofollow? As my current newbie knowledge tells me is that I should use rel=nofollow as an attribute in every link that goes outside my domain in order not to leak my current PageRank. Or maybe I'm wrong?
now google even devil - if the post in blog you include link and the link is not "nofollow" they will not index the page
That's fine if you're referencing a story. But, if you are trading links with somebody, don't use it; they'll get mad at you.
It's just an attribute that tells the search engines to ignore a link. A good reference would be the "Jedi Mind Trick" from the Star Wars movies. Just as how Obi Wan once said "These are not the droids you are looking for." the rel="nofollow" attribute tells the search engine spiders "This is not the link you are looking for." It's best used to prevent PageRank "juice" from flowing from your page (note I said page, not site) to another page (again, note I said PAGE, not site) that you don't want it to go to (such as affiliate and referrer links).
the nofollow prevents search engines to be index any urls which putted with the nofollow. If you don't want PR of your sites to dropped, you can added to the nofollow of any urls to your sites.
When you use that tag the link is there for us -ordinary people but it is not there for them -search engine bots.