I have a little alcove in my bedroom (it is about 5 feet wide by 9 feet long) and have used shelves/desks from Ikea. I loved these because they are thin. Like Joan suggested, I have used under the desks for storage - I have a filing cabinet for my 8.5x11 paper and rolling carts for other supplies, and I use a ton of photo boxes that I buy when they are on sale at Michael's. I also created little strips of paper to put at the front of the clear drawers of the carts and got doors for one of my bookshelves, so I wouldn't see the clutter inside.
For me, aside from labelling everything, part of what worked was keeping it all white - this made it look cleaner.
Neece has a great point too - use under the bed and any other space you can find (i.e. garage, basement) for out of season/bulky storage.
I have some pictures in my gallery (about the only thing I have pictures of there - lol!), but I would definitely check out Ikea - even if you don't buy anything, they have great ideas.
Good luck and have fun! I always love to organize - I think this is half the fun of this craft!