Responsible for SEO and you do not have a ton of SEO knowledge? If you answered yes proceed to the next question. Did you know a simple wrong tweak can have your entire website de-indexed? If you answered no then you really need to read about SEO and get a firm understanding. The last thing you need is to erase your company site from the Google and Bing index and not have an answer as to why the site felt deep into oblivion. Sooner or later someone will figure out why and if your actions caused the disappearing act then you might find yourself packing up your things and disappearing from your job.
Search Engine Optimization Secrets by Danny Dover is the first book you should read. It caters to several audiences: The SEO newb, an SEO with some knowledge and there are a few nuggets for the advanced SEO. Do yourself a favor learn about SEO if you are responsible for SEO.