hi Fj, and welcome to sevenforums,
if you've been a vista user, you'll feel instantly at home with 7.
you've already identified the major UI change, namely the taskbar where you can pin icons. Taskbar - Pin or Unpin a Program
then there are jumplists: Jump Lists
- once you've got your head around them, they can be a major aid to productivity, allowing you to quickly open folders of your choice in explorer, or favourite files in any app.
there's hardly any learning curve to negotiate - unlike windows 8 - but don't get me started on that.
oh, and there's aero snap too. Snap a Window to a Side
none of these features are forced upon you, but are very handy once you've learned them.
of course there are other changes too, like homegroups: Homegroup - Create
, and more, but most of them make sense and are simple to learn.