How can you tell if your feathers are Right Wing or Left Wing?

[Yazoo Bowhunter]

I'm so confused.  I cannot tell if my feathers are right or left wing.  When looking at a feather placed on the shaft of an arrow, the little "extra" piece of stuff hangs to the left side.  You know what I'm talking about.  Basically grab an already fletched arrow and look at your feather looking straight down.  One side of the feather has a little ledge, per ser, and I need to know what that ledge means.  All my feathers had the little ledge - ie extra material - on the left side, thus, my feathers are left or right winged?

See this is why I'm confused.  Guy that did my fletchings along time ago did them left wing and all the little ledges are on the left side of the feather.  But the guy at the store today sold me what he said were right wing, but the ledges are on the left side.  Thus, someone's wrong.    Then I went to a different store a few days ago and guy sold me what he said were right winged feathers and the little edge is on the right side.

Someone please explain how to tell using my little edge of extra material terminology.  I don't understand anything else.
Also, what happens if you fletch a left winged feather in a right winged gig, or vice versa?

[Orion]

If the catch lip is on the left side as you look at the arrow from the nock end, i.e., pointed away from you, you have right wing feathers.  For confirmation and a fuller description, go to Trueflight's web site.

[JiminTexas]

Look down the fletching from the nock end (wider end) and if the little shelf on the bottom of the feather sticks out to the right like the ltter "L" it is left wing. If it sticks out to the left like a backwards "L" it is right wing.