Assessing quality of power

I am now at the point of looking into power conditioning-regeneration and have read many of the long informative but highly technical threads here. My question: Is there a simple way to assess the current quality of your power, aside from purchasing a conditoner and asessing the result? For example with dirty power can you hear that through your speakers when system is powered but nothing playing (CD player on Pause) and can voltage flucuations be assessed by a simple Radio Shack instrument?

I suspect my power is fairly clean. I live 1/4 mile from anyone else, have my own transformer on the pole 30 feet from the house, have wiring and box that are about 5 years old. My listening room is in a new addition with its own new service, so all motors such as the frig are on an entirely different service box. There is one computer and several rheostats being served off of the addtion box, but all are usually off when I am listening to stereo. My lights do dim when the amp first turns on. What should I look for? How can I determine if dedicated lines or a power conditioner would yield more bang for buck. Thanks