your amps should be wired , main feed (permanent 12v+ through a 'cap' if big power jobbies) through a fused line from your positive terminal on your battery, your 12v- (or earth/negative etc) should be connected to a suitable earthing point some where in your boot, and your remote switching line should run from the 'remote/amp' line from your head unit along a path of your choice (not near rca/signal wores though as can cause interferance) to your amp. then when you switch your head unit on you should get your amps to crank up (provided you havent made a common mistake which is where some peeps connect there amps remote wire to there 'electrical ariel' out put from head unit thinking it does the same thing, on alot of head units now the ariel (when connected) will only come up when the tuner is on, so if you have a cd on (with ta etc turned off) you will sometimes not get any power to your amp.
im sure if you post a thread in the ice section some one in there will prob be able to help more??
Gaz