I am trying to figure out how to connect a light, single pole switch, receptacle and a line that goes to another room. The "hot" is coming into a rectangular box for the light fixture. I can figure out how to get constant power to the receptacle and the room further down the line, I am having trouble running the hot so it will switch on and off the light. Any help is greatly appreciated

If you've figured out the constant power, then you know you have the incoming black hot wire connected to the outgoing black wire, and the incoming white white going to the outgoing white wire.

For a light and a switch, connect the black wire from the switch to the black (hot) incoming wire from the panel. Then connect the white wire from the switch to the black wire of the light. Basically, you are using the switch to interrupt the current to the light. Then connect the white wire of the light to the white wire from the panel (and the white going to the other room)

The ground on the wire from the panel gets connected to the ground screw on the box, and then to all remaining ground wires