Hey Rich, I not going into a "how to" here but I highly reccomend the Labelle Lubricants for model railroad use. You want to use the ones that are plastic compatible. I've seen many a set of gears/axels ruined by using the wrong kind of oil and grease.
In general if it moves it probably needs to be lubricated. With your older locos that you got it would probably be best to clean as much of the old oil and grease off as you can with alcohol and then use fresh lubricant.
When oiling use just a small amount...a drop about the size of the point of a needle is just about right. When oiling motor bearings be very sparing with the oil so that it doesn't creep into the commutator of the motor. Oil doesn't stay on gears too well so you want to use some kind of grease. Again I reccomend Labelle Plastic Compatible Teflon Grease. For metal gears I reccomend their gear lubricant. But if they are metal and plastic use the teflon grease.
Just go about cleaning and lubricating your locos as if you were doing a watch movement and you'll be amazed at how well they run.
Hope this helps.
