Track Monitor Icon

When recording tracks what should the setting be under the Monitor icon? OFF, ALWAYS or AUTO INPUT

That depends...if you need to hear the output of the track (when using ampsims, FX on the vocals or playing VSTi) you want the input monitor on, if you are using already "finished" sounds from e.g. a real amp + mic or your hardware synth, you maybe want to use the direct monitor path of your interface for its lower latency.

Thank you for taking the time to help preschoolers like me. I'm still not fully understanding this and the manual has very little info on this button. Maybe you could list the fuctions for each or just tell me where this should be for the style of recording I'm doing.(I'm recording modern bluegrass all acoustic with mikes and pre-amps dry no effects. Sorry! Should have put that in the first post.) I guess what I need to know at this point is what should this be set to when I record the dry audio and then where it should be when I add effects later and play the track. Monitor input ? Monitor input( Tape Auto Style )? Monitor Track Media When Recording ? It gives me the choice for checking one of the first two and the third or having none of them checked.

"Monitor Input" is what you want. The third one is when your over-dubbing and want to hear any Clips already on the track. As you sadi, you can enable this one regardless of what input monitoring you choose. And the second one is explained well here:

The funny thing is having none of these monitor settings check seems to sound the best. Less backround noise. More real! What is happening when none of the three opptions are checked?