Okay, I'm pretty sure your Panny doesn't have a built in hard disk, meaning you can't record anything directly to the TV. Two things I can think it might be:
1. It's an option to set the TV to switch on and go to a certain channel at a certain time. This then allows you to set up an independent recording device (like a PVR or a VCR) to be set to also switch on at that time and record the input from the TV.
2. Some of the Panasonic's have an SD card slot that you can put a standard SD card into and record to. Although the model you've quoted above doesn't have this feature, it might be the TH-42PX700 which does.
So I think you can't actually direct record on the Panny (certainly not the model quoted anyway), you need an external recording device hooked into it.
This is the Viera link setting in your tv. You need a Viera-compatible DVR linked to the set. When that's done, you can set up a recording via the TV, and the DVR will pick up on it automatically and record it for you.