How high I should install a 52 inch TV on the wall?
First, sit on your couch in the ideal viewing position (ie: where your butt imprint is).  The bottom 1/3 of the TV should be at eye level when mounted.  Everyone has an opinion about exact positioning, but this is more or less the general rule of thumb I've found from various sources, and it has always worked well for me.

I find most people mount them too high. No one likes sitting in the front-row at the movie theater, so why do it at home?