I'll add to this. And as a disclaimer, I am not a pilot (yet), or controller.
I was honored to be able to visit both NorCal TRACON and Sacramento Int'l Tower a year or so ago with Inigo and a couple of other people. All we had to do was Give them a call a couple of weeks out, and work out a date and time for a tour.
I was also able to visit Omaha Tower and R90 TRACON when I went home to visit my parents. Once again, a simple call telling them who I am, and if they have available time, could I have a tour. They agreed, and off I went.
Next on the plate: L30.
Operation Raincheck is still around, so you could reference that, but be prepared to answer some questions if you do. Google for that, and you should find out all you need on that.