Engine Idle

I've had this problem since I've driven the car back from OH. When I picked the car up, it idled correctly. Sometime later in the trip back, the idle speed droped and it won't idle, only stalls. It does this both when cold and at temperature. I have to keep my foot on the gas or else it will stall. Makes driving a 4-speed interesting, although I' ve gotten good at applying the brakes while keeping a little gas flowing  Ideas appreciated on what I should check first? Learning as I go here....

Dave:

     Thanks for the reply. I guess I should have tried the simple thing first! I know the basics and have a general understanding of how things work, but very little "hands on" which is so critical. So I dug out the shop manulal, figured out where the idle screw was, and upped the idle a little bit. The engine was still warm from a ride earlier today (boy does that engine bay hold heat well!) It now idles like a champ. Guess I just needed a little encouragement .