run a good gauge with a fuse in the line from teh battery or just get a good breaker that you can turn on and off as your main power and find a switch that can handle the power and run you positive from the inverter to the breaker or fuse wire from the battery and ground the other to the fram of the car like under the center consel thing. i am a shitty speller. i ran a 2 gauge from my battery to a breaker switch and from there to a ditribution block that splits into 2 4 guage adn from there into 2 4guage to 4 8 guage blocks giving me 8 8guage lines (2 to amp) and rest for other shit. then i grounded all to the frame.
as far as telling which wire is which one should be black and the other should have a white line on it...white line is pos.
if not then just open the ciglighter plug and see which side plugs where and you can tell from that. center of plug is positive and outside is negative

Talon
97'Talon Esi
Injen short ram
stock 16" rims <---heck yeah !!!
AEM cam gears