My kids' rooms are the same size. We have in each room: a twin bed with underbed storage drawers, a night table with a bookshelf underneath, a low dresser, and a bookshelf. We installed elfa in the closet and frankly I now wish we'd never even bought the dresser - the elfa'd closets provide more than enough room for clothes, toys, storage of art projects, extra blankets, etc. They keep toys in the underbed storage drawers (the only problem is that only one drawer is really usable b/c the other drawer is partially blocked by the night table). It really works fine, although my kids are young (6 and 8) so don't know what needs they may eventually have!

Get really tall bookcases. Our DD has a room about that size.

look at more modern design places like ikea, west elm, and cb2, they tend to have more options for apartments and have cleaner lines. Also measure everything beforehand.

Get a captain's or mate's bed with drawers underneath. Put additional shelving in the closets so you can do away with one of the dressers. Use wall shelving for more storage.

Consider getting a loft bed that has drawers underneath. Do the rooms have a closet? If so, instead of getting a dresser, get a closet system installed.

Our house has 2 small bedrooms for the kids (each around 9 x 10). For each room we need a twin bed, dresser/mirror, tallish chest of drawers. Where should we look?