Photos and captions contain important information.
Step 1: Before Beginning
Table saw, Miter saw, Hand drill, Tape measure.
Masking tape, couple bolts, couple lags, couple drill bits, One 2x4
The approximate size of a 2x4 is 1.5x3.5" by however long.
The size and location of mounting holes on the back of your TV or monitor may vary from mine. The length, width, and type of bolts needed will also vary by TV, along with the size of each wooden component. One thing to keep in mind is the standard spacing of studs in common construction - 16" on center.
Step 2: One 2x4
Two vertical pieces, and three horizontal pieces (two cleats and one spacer).
Again, these lengths are based on the spacing of the mounting holes for my TV - there are four holes all spaced 16" apart. I added three inches to avoid drilling mounting holes at the very end of the cleat boards.