Pretty straight-forward question ... there is paid membership at seomoz.org that provides a whole load of promised benefits... http://www.seomoz.org/users/premium Has anyone tried it? Worth paying for?
i m their blog reader and a big fan, if i had the money, i would certianly gone for it. So if u can afford it,dont think twice.
Fishkin's articles (Beginner's Guide to SEO and Google Ranking Parameters) are the ones I'd advise for anyone. I don't endorse having premium membership on blogs, and I didn't buy it, but you may try it out.