rob... the squirrels around here are hitting the hickories pretty good. Find a hickory with a pile of fresh nut scraps (cuttins') and hide near by.
Use your ears you can hear the nuts fall occasionally. You will also hear their teeth chiseling away the hard hickory nut shells and it can sound like rain hitting the forest floor when several are in a tree.
Usually if you find a popular tree, every squirrel in the area will visit it. I've seen as many as a dozen in one tree.
Use your eyes as well. Watch for the telltale and out of place movement of limbs and leaves.
You can often see the nut pieces falling around a good tree.
Remember, anything falling from the trees (like a lone leaf or piece of leafy limb) this time of year was most likely cut or dislodged. Look up it's a sign.
When a squirrel is in the tree you can wait him out if you are patient... he WILL show himself.
Watch for obvious routes of travel. Squirrels will often turn certain limbs or logs into little highways. Take advantage of it.
If you have a squirrel hiding behind the trunk of a tree, you can often chase him around to your side.
Just wait for a while and be absolutely quiet. Pitch a stick or nut beyond the tree and the squirrel will often scooch around to your side.
Be quick.
Foremost, have fun buddy.
http://www.tradgang.com/upload/charlie/fallingsquirrel1.jpg