Step 1: Equipment.
MDF (cut to required size)
6x2 timber (cut to required length)
2x2 timber (cut to required length)
2x joist hangers
Basic tools - Drill, screwdrivers, saw etc.
Step 2: Wall Fittings.
After you have done this, cut your MDF to the size you like (it differs from house to house due to the amount of timber in the wall, if it is an exterior wall etc.) and attach it to each wall making sure they are parallel to each other.
Then attach the joist hangers to the MDF by screwing them on, making sure that they are again parallel.
Step 3: Back Support.
During this step, you must make sure that the top of the 2x2 is parallel with where the top of the 6x2 will be.
this step isn't necessary but it really helps, the traverse board might flex if this step isn't taken.
Step 4: Main Board Fitting.
Step 5: Main Support.
just simply, cut it to length and then screw it on top of them.
Step 6: Climbing Holds.
when screwing in professional holds, start with a drill and finish off with a screwdriver, making sure not to screw them in too tightly, as they may break.