Have a look at some of the scraprooms on here in the gallery or google it...you'll find a lot of ideas!
My scraproom is also a spare bedroom that is approx. 10x11 but it is also our home office and my son's schoolroom (I homeschool)....
So we put a desk around two side of the room, along one wall and then also under the window wall. It works great and I use under the desk space for a small filing cabinet etc...
I have a large bookshelf on one wall and an Ikea Expedit system on one wall that is all good storage.
Above the desk are shelves and my ribbon holder...

Good luck and have fun with it!
Alison