How do you know when / if you need a pressure plate; when is IT worn out?

This is my first manual trans car / experience so I'm on the learning curve!

Is there a "rule-of-thumb" for wear-and-tear of normal type driving, like two clutch discs to every one pressure plate? Is there anything you can tell by pedal feel or how it shifts or acts when engaged to know there is a pressure plate problem?

Also, how do you know when you just need to adjust the fork rod?

My car is a 71 Charger 500, 383 4-speed with 106,000 miles. I'm just now getting it running to where I'm going to take it for a drive and I don't know what to expect with the clutch and transmission.

I found this article and am reading it and trying to absorb what it says: http://www.procarcare.com/includes/content/resourcecenter/encyclopedia/ch20/20TSclutch.HTML

Any advice?