K, because you asked nicely..
First, find yourself a spare car battery. If not, you can use one that is in your car, (and no, you don't have to take it out.
Prepare a few things:
In-Line 20-40 Amp fuse
Various lengths of wire that are suitable for the amp to run
Wire clippers
Butt connectors/crimpers
Rig your power wire with the inline fuse and prepare a lenght of wire for your ground. Connect the fused lead to the (+) terminal on the amp, as well as the (+) on the car battery. Next, connect the other wire to the Ground on the amp and to the (-) on the battery/any other suitable chassis ground will also do. From there you will need a small double ended aligator clip or length of wire that you will connect the (+) to the REMOTE on the amp. This will turn the amp on. If you amp has a power light, it should be illuminated.
This is the first test, if you see a light, there is a chance that the amp is o.k.
You can then pull out the fuse, while you attach a speaker to the output terminals of the amp. Remember, the speaker should be able to handle any power that the amp could give it.
Now, feed a signal into the amp via the RCA jacks, Plug your fuse back in and see if you are getting any sound on the outputs. You may have to initially adjust the gain of the amp to hear anything, or it may already be set.
From there you can tell if the amp has any potential. You can use that speaker to check the other outputs to make sure that all the channels are functional.
Some HQ amps have thermal/short circuit protection that will help prevent them from blowing up, there will usually be a LED that will light up if there is a problem with the amp.
If you could provide a brand/model number I may be able to help you out with any specifics.
BTW, if you have access to a ociliscope, I can tell you how to get the MOST bang for your buck from your amp!
-sF