Binding basically means sticking, or being jammed between something.
In this case, a binding pin is one that is 'stuck' (jammed) between,
where the plug meets the shell.
Think of holding a bolt with a pair of scissors. The bolt is bound in the same
way as the pin in the lock.
You will know a pin is binding, because you won't be able to push it up
because it is 'stuck' instead of having a springy feel of movement like
the rest of the pins in the lock.
If all of the pins are binding/stuck, there is way too much tension for picking.
Put your tension wrench in, turn it so that they all bind, and have a feel
of what binding pins feel like. (Don't try picking it, JUST FEEL).
Now do the same thing, and try picking it softly, and SLOWLY release
tension until a pin is EASY to move.
YOUR TOOLS SHOULD AT NO TIME BEND, WHILE DOING THIS.
Also, check out these animations by Deviant Ollam:
Just start from the start, and about the fourth one might be real helpful.
http://deviating.net/lockpicking/topics.html
Hope that helps a bit.
