I've read several guides/articles that mention stealing from NPC's (FO1); but I haven't been able to discover how. Any one care to explain how this is done?

kill 'em

See this http://fallout.wikia.com/wiki/Steal

Either choose the skill from the Skilldex menu and then left-click on an NPC, or just press 3 on your keyboard and then click.

Ahhh! Thanks insomnium, that's what I wanted. The link was informative; but, didn't say how it was actually done, only that it was done. (If that makes sense)

Yes it does. I actually read insomnium's post and thought - Doh! that's what the OP wanted.

The hotkey for stealing will save you a lot of time if you have a very low steal skill, for saving and reloading over and over again.
Like in FO2, the Bozars you can STEAL from the guards at the bazaar in the NCR... wow, there are a few ways to horribly exploit the game.

FO2, the merchants in San Fran are the best people to steal from. you could have low skills and end up with alot of cash form these guys.

In the first 2 Fallouts, I basically stole whatever I needed.