I consider Search Ranking Factors by SEOmoz the most relevant resource for SEO, since it gives you reasons on why do a certain activity, rather than another. It can help you a lot in putting priorities – “this is important and easy to do, while this is neither important, nor easy to do”. And, following this, you know how to take a decision.
IT is: Information technology (IT) is the acquisition, processing, storage and dissemination of vocal, pictorial, textual and numerical information by a microelectronics-based combination of computing and telecommunications. SEO is: Search engine optimization (SEO) is the process of improving the visibility of a website or a web page in search engines via the “natural” or un-paid (“organic” or “algorithmic”) search results. Yet, I get to see this confusion quite often – “You’re in IT”; I’m not; I may be in marketing, PR, communication, IT also; but never just IT; IT is, actually, quite a small part of things. Sure, I am at a computer most of the time, sure, I do know IT things, have an idea on a lot of processes in IT; but that’s not my specialization.