Those of you who are knew into Search Engine Marketing and want to understand about links, then now is the chance to learn directly from Google itself. I have been learning about SEO from last 5 years but since no information was ever given by google, we mostly had to read from other experts.

But finally Google explains it all in their blog. Its a 4 part series where they explain different types of links in each article.

You can read more at http://googlewebmastercentral.blogspot.com/2008/10/links-information-straight-from-source.html