In this diagram, a light switch and receptacle are wired in the same box. Both devices are spliced to the same hot source and the neutral to the neutral on the receptacle, and through to the light fixture located in a separate box.
Here the exhaust fan is controlled by a timer instead of a switch. There should be two hot wires and a ground coming out of the timer casing, splice one of these to the hot source. Spice the second to the black, cable wire running to the fan. Splice the source neutral to the white cable wire and the ground to the ground wires. At the fan splice the wires, matching the colors of each.
The source hot is spliced to the red wire which is connected to the bottom terminals on the switch at the other end. The black wire is connected to the top terminal on the switch which runs power back to the fan where it is spliced to both the black and blue fan wires.
Here a gfci receptacle is added at the end of a row of duplex receptacles for single-location protection. The first outlet is connected to the source and 2-wire cable runs from box to box. All wires are spliced with a pigtail at the devices to pass current from one to the next. The load terminals on the gfci are not used and it does not protect the other receptacles in the circuit.