The general consensus is to place the meter at the "sweet spot," pointed straight ahead toward the TV and center channel speaker, and placed at about the exact height your ears would be.
I have heard a variety of opinions as to what angle the meter should be tilted. I have gone with tilting the meter up at about a 45 degree angle. Do not aim the meter at each individual speaker.
Placing the meter on a tripod, if you have one, is the ideal. This allows the meter to be held steady in the same place, allows the user to move out of the way so his body doesn't become a factor in the readings. Obviously you wouldn't want your body between the meter and the speaker being measured, but neither do you want to be in a position where your body reflects the tones coming from the speaker back toward the meter. It's a tricky business. That's why the tripod is a good idea.
An alternative to the tripod is to prop the meter up on something that keeps it at the right height and angle, but you've gotta be careful about that reflected sound thing.
Since you have the M60s, in the rear I'd go with the 22s, or M2s if you want to save money.
