Measure the length, width and height you will build the unit on a given wall. Don’t begin construction until you lay out the design in detail, defining where the television, DVD player and other items will fit. Figure out the best route for bringing electrical wiring into the unit for lighting or outlets for the media equipment. Run this wiring down through the attic, for example, and into an allowable space between the unit and the wall studs. Draw everything in detail on graph paper, including shelves and door spaces.
Construct the basic shape for the unit framework, using 2-by-4-inch boards. Locate existing wall studs with a stud finder. Secure new framework for your entertainment unit to existing wall studs using 4-inch screws. Cut the framework pieces for the cabinetry, mitering all corners for a better fit when covering is added. Use screws to attach all component parts of the framework. Secure the bottom plate to floor joists, checking with a carpenter‘s level to ensure the framework is plumb. Use wood shims, if needed, to get the framework squared up.
Run electrical wiring inside the back of the cabinet before covering the framework with drywall or other materials. Use conduit to house the wiring. Cut drywall, veneer or bead-board paneling to line the shelving spaces and wall sections of the unit, using a drywall saw and jigsaw. Use bead board as a durable material for lining sections that will hold books. Cover the bottom of the shelf where the television will sit, using 3/4-inch plywood. Glue wood veneer over the plywood. Use a fine-toothed saw blade to cut any covering you use, so there will be minimum gaps along seams.
Finish up any drywall seams by taping the seams and covering them with joint compound. Sand the seams smoothly, so seams or dents in the drywall do not show. Use joint compound, and sand the drywall seams at least two more times, working toward an overall smooth drywall covering.
Nail crown molding across the top of the cabinet for a built-in look. Cut wood trim to fit around openings for closeable doors, mitering all corners of wood trim. Install unfinished pre-made doors that you paint or stain to match the unit. Use hidden hinges that do not show -- for a more professional look. Nail crown molding across the front of the cabinet at the floor level for a totally built-in look.