I used to know what setting to use on the volt meter, but I'm totally lost right now

 

You will use the OHM setting the "omega" symbol or "horseshoe" isolate the wires and measure the resistance. Each wire will be different because wires are a certain resistance per foot. Most of the time that amount of resistance per foot is labeled on the wire.

 

You want to have about 40-50 OHM's of resistance per foot. At least thats what my MSD 8.5mm wires call for, IIRC but I could mistaken.

 

Replace them. If the car runs better, you needed new ones.

 

Pulling the wire off the plug while the engine is running works good for me!.

Ouch Ouch Ouch is a weak wire.

Aaahhhhhhhhhhhhhhhh! is a good one!

 

Factory wires are generally "good" if resistance is under 1400 ohms/ft,general performance wires ie; regular Accels - 700 to 800 ohms/ft,Accel 300+ Moroso Blue Max Jacob's - 250 to 450 ohms/ft,MSD 8.5's 40 to 50 ohms/ft and then Moroso has a new wire that's 35 to 40 ohms/ft but they are double the price of MSD 8.5's.IMHO MSD wires are probably the best made for the dollar.
A low tech way of checking if your plug wires are breaking down is have the motor running in a dark garage or after dark.A leaking plug wire will give off a bluish aura.Checking with a multimeter,digital preferred,is the best way set on OHMs as nelapse suggested.

 

Most performance wires have less resistance. So a stock wire will be much much higher.
One other way to check for a faulty wire is to pull a wire in a running motor and monitor the rpms for each one.. make sure you put the wire back in before you pull another and to use spark plug wire pullers you will get the **** shocked outta you or burned by the exhaust mannys.
If you need new wires go to Autozone and buy the Bosch premium set its like 30 bucks... and has a life time warranty. They will take them back even if you think its bad or if you screw up a wire or burn it on the header... doesnt matter... new wires for life. Performance wires are good... but you really wont notice much of a difference between performance wires and the bosch ones.