Mount the plywood on the wall (ask hardware store for proper mounting instructions). This kit by Mountain Equipment Co-op shown below is a great way to get your home wall started. It includes virtually everything except the plywood. The hold selection varies from kit to kit (no choice), but each kit includes a balanced blend of big, medium and small holds, screw-on hand and foot holds, micro bolt-on crimpers, really big roof jugs, and positive-to-grab little juglets.
How cool is the half court design painted on the floor and the mounted basketball head board?