I want 2 ( maybe 3) outlets controlled by the same switch. Easy enough. But, in addition, I want half of each outlet controlled by the switch and the other half of each outlet always hot. Is there a wiring diagram somewhere for this? I just haven't found it. A diagram would help confirm how I think it should be done. They will be in the same room and the wiring will be relatively easy to run.
The switch opens or closes contact on the hot wire leading to the outlet(s) (receptacles) that you want to control with it. It "makes or breaks" the hot connection to the load. An additional unswitched hot wire would need to run to the receptacles that will not be controlled by the switch.
So... you will need a run of wires that includes a switched hot, an unswitched hot, a neutral, and a ground wire. If you plan on using NM sheathed cable (e.g. Romex) you would need 3 conductor w/ground, e.g. 12-3 w/ground.
If you plan on using common duplex receptacles (the devices with 2 "outlets" on a single frame), you will need to break off a little jumper tab that ties the wire contact plate under the terminal screws together on the hot side, to isolate the switched receptacle from the unswitched.
No diagram is really needed because if this does not make sense to you then you ought to hire an electrician.