The most comprehensive guide I saw that teaches what to look for I have copied directly from the site in an attempt to create some redundancy of information on my own so I can retrieve it easier. The original is http://www.blifaloo.com/info/lies_eyes.php

Eye Direction and Lying

Eye Movement and Direction and How it Can Reveal the Truth or a Lie
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This is a continuation of our previous article ” Detecting Lies“. Many comments by our visitors have asked about how eye direction can indicate the presence of a lie.

So can the direction a person’s eyes reveal whether or not they are making a truthful statement? Short answer: sort of. But, it isn’t as simple as some recent television shows or movies make it seem. In these shows a detective will deduce a person is being untruthful simply because they looked to the left or right while making a statement.

In reality, it would be foolish to make such a snap judgment without further investigation… but the technique does have some merit. So, here it is… read, ponder and test it on your friends and family to see how reliable it is for yourself.

Visual Accessing Cues

The first time “Visual Accessing Cues” were discussed (at least to my knowledge), was by Richard Bandler and John Grinder in their book “Frogs into Princes: Neuro Linguistic Programming (NLP) ” From their experiments this is what they found:

When asked a question a “normally organized” right-handed person looks (from your viewpoint, looking at them):

Up and to the Left
Indicates: Visually Constructed Images (Vc)
If you asked someone to “Imagine a purple buffalo”, this would be the direction their eyes moved in while thinking about the question as they “Visually Constructed” a purple buffalo in their mind.

Up and to the Right
Indicates: Visually Remembered Images (Vr)
If you asked someone to “What color was the first house you lived in?”, this would be the direction their eyes moved in while thinking about the question as they “Visually Remembered” the color of their childhood home.

To the Left
Indicates: Auditory Constructed (Ac)
If you asked someone to “Try and create the highest the sound of the pitch possible in your head”, this would be the direction their eyes moved in while thinking about the question as they “Auditorily Constructed” this this sound that they have never heard of.

To the Right
Indicates: Auditory Remembered (Ar)
If you asked someone to “Remember what their mother’s voice sounds like “, this would be the direction their eyes moved in while thinking about the question as they “Auditorily Remembered ” this sound.

Down and to the Left
Indicates: Feeling / Kinesthetic (F)
If you asked someone to “Can you remember the smell of a campfire? “, this would be the direction their eyes moved in while thinking about the question as they used recalled a smell, feeling, or taste.

Down and To the Right
Indicates: Internal Dialog (Ai)
This is the direction of someone eyes as they “talk to themselves”.

The Gist of it…

How this information is used to detect lies:

Example: Let’s say your child ask’s you for a cookie, and you ask them “well, what did your mother say?” As they reply “Mom said… yes.” they look to the left. This would indicate a made up answer as their eyes are showing a “constructed image or sound. Looking to the right would indicated a “remembered” voice or image, and thus would be telling the truth.

Final Notes:

*** Looking straight ahead or with eyes that are defocused/unmoving is also considered a sign of visual accessing.

*** A typical left-handed person would have the opposite meanings for their eye-directions.

*** As with other signs of lying, you should first establish and understand a persons base-behavior before concluding they are lying by the direction of their eyes.

*** Many critics believe the above is a bunch of bull***t. In my own experiments I have found these techniques to be more true than not. But, why not find out for yourself? Make up a list of questions that like the sample ones, and give them to your friends/family anyone who would be your guinea pig, observe their eye movements and record the results.