Clear out your classroom -- maximizing the amount of space by reducing the amount of things in the room. Remove all of the desks, which will be replaced, the bulky storage units and any items that are not used often.
Bring tables and chairs into the classroom, stacked, and place them where they will go, stacked. Leave these items stacked for maximum amount of space while you are working on the room. Bringing them in first is important because they are the largest and most important thing in a classroom.
Bring shelving units complete with bins to line the shelves. Place the shelving units on a side wall of your classroom, so they will be close to -- but not in the way of -- tables and chairs. Fill the bins on the lower shelves -- the ones accessible to students -- with supplies used most often. Fill the bins on the higher shelves with extra supplies, teacher supplies, etc.
Create a reading center using a corner of your classroom. Place two tall book shelves in a corner, one on each wall so the sides of the shelves meet. Then put one smaller bookshelf on the outer side of each tall shelf. Anchor the shelves to the studs in the wall using shelf anchors, a cordless drill and 4-inch wood screws. Place books on the lower shelves. The higher shelves can be used for additional storage, if needed.
Arrange the tables and chairs in the center of the classroom.