Hmm... I don't know if this is a serious problem...

Example: when the brakes are applied, the battery gauge goes down a bit. When the turn signals go on, the gauge goes up, down, up, down as the lights come on and off.

Is this a cause for concern? Battery and alternator are good, as far as I'm concerned.

I have searched the forum and came up with nothing... I might now know what I'm looking for

This is no cause for concern. You're always going to have some voltage drop/gain whenever you turn something on/off. In your case, when you apply the brakes, your engine is turning slower so you will probably see a slight dip in voltage. And, like you said, the volt meter goes up and down when your turn signals are on. About the only time you should be concerned that you have a problem with your charging system is if the Amp(Alternator) light comes on. Which is why you should check to make sure that light comes on when you start your car.

i was wondering about that very thing. thanks for the answers. also i got talked into going to the dairy queen drive up one very hot night and as we idled there in the line (for what seemed like eternity) my alt guage started dropping well below the 13 v line. if i gave it some gas it would go back up. i had my air on and figured that had alot to do with it but i dont supposed its a good thing.
the alt was rebuilt about 4 months ago so i dont think its bad. any ideas?

It may be the alternator. Sometimes if it is not a good rebuild job then it can't keep up. Also may be the battery or connections at the battery.

If the oil pressure drops when you turn the headlights on then it is probably a bad ground.

Nope- not an issue. unless the volt meter dipps really low and your headlights dim, then you need a new alternator, but that guage seems to be very sensitive, I've had that on my89 SSE also