Power for amp and aftermarket radio

[1970Moparmann]

Guys,

I haven't put an aftermarket radio in any of my cars yet, so I have some questions.   I'm putting in an amp and a radio.

Amps usually get powered up by a connection with the battery and fuse.  BUT, where is a good source for the radio?  I believe someone a few years ago mentioned the starter relay? 

Also, what would you suggest to connect to the "remote" wires to?

Thanks!

[68 CHARGER R/T]

usually the remote wire get hooked up to your amp it turns your amp on and off when you turn your radio on .the main power wire goes straight to the battery and have an inline fuse close to the terminal  ,ground the amp to a bolt  somewhere in the trunk make sure the surface is clean from paint  the deck i just wire it up through the fuse box for the power source