i was wondering what all the wires should do for towing... i have the 4 wiring system... i know the white is ground and there is a brown i think that should be running and then the green is it right or left signal and same with the yellow

 

You'll generally need an adapter to split/combine the Toyota wiring to the trailer. Toyota uses separate bulbs for running light, brake and turn signals. The trailer typically uses 1 or 2 bulbs for the same:
- http://www.etrailer.com/faq-wiring.aspx