In my last employment, we had an UX department, though was only 1 person and I opinionated with her here and there... We got the same thing as what UX is for the rest of us and "isn't that UI?" kind'a answers...
a good article that we referenced a lot was a Smashing magazine one that not only shows what UX is, but gives the sense that it is very useful to have.
You also have been asked to develop a team website, I would suggest that you do it as simple as possible, and why not a 2 website page? one with the "buttons and links" correctly places and formatted, and another page with exact the same content but hard to find "buttons and links" and a the end "This is what we do", on the other "This is what we avoid you end doing" kind'a pitch...
UX is huge, even a simple question as how a carousel content move in a table/mobile device when we click the left and the right arrows brings so much input and questions, and it's up to the "UX department" to guideline for everyone to follow and the customer get the same amazing experience across any interface...