When I load up POD Farm or Amplitude into a track to record, the "live sound" has a little bit of my dry guitar signal in it.  When I play it back, it's fine - the "pure" plugin sound.  I don't see any settings anywhere to change this, but I could be missing something.
 
Any ideas?  Thanks.

Is there a "mix" knob on your interface that could be allowing some slight "raw" guitar signal into your phones (or monitors)?

I would check for a mix control on the plugin. Set to 100% will mean either fully dry or wet. 

If your soundcard allows you to send an out to your monitors in addition to your DAW then you will hear both when you are recording but only the recorded sound when playing back. I've experienced this myself.
 
Regards,

mmorgan
If your soundcard allows you to send an out to your monitors in addition to your DAW then you will hear both when you are recording but only the recorded sound when playing back. I've experienced this myself.
 
Regards,

Bummer.  It's not that bad I guess, but it just adds an extra step now where I'll have to create the tones I want outside of SONAR.  Thanks 

Most likely you've got some direct monitoring engaged on your audio interface. You'll need to defeat this and monitor only directly through SONAR's audio engine.

What Brandon said.

For my audio interface in my control area for it I can mute the channel that has the input signal (which is dry). With Sonar having the input monitor lit I then only hear the processed signal on the track. At low latency it sounds like real time effects on the signal. All of the adjustments to find the right sound can be done within Sonar or within the effects within Sonar that way.

That control may be a simple mix knob that mixes the input signal coming in from your guitar with the output signal coming from Sonar.  Sounds like it may not be set all the way to the output side, letting a little it of the dry input signal mix with the output from Sonar.