In the VCR Plus+ (no TVGOS) the "cable channel changer" thing is a table you fill in with your local cable channel numbers, lined up with the numbers assigned to stations by the Plus system. The Sunday TV newspaper guide published a list of 'universal' VCR Plus channel numbers. You had to go back and forth in the list when you entered it, as most of it was not numerically sorted. Theoretically you had to line up local cable numbers with universal numbers only once, but if you lost power for awhile, or the cable company moved stuff around, you had to fix it.
Since May, most newspapers don't list Plus codes. You can get them online, but that won't save you any time.
Since my VCR is hooked up to a converter box with timer, I tend to use a single VCR timer on the VCR side of things for all prime time recording, and disable it on the days I don't want to record. Then I only have to fuss with setting a timer for the VCR side if I want to record something outside prime time.