Line lock?....

Can anyone tell me how these things work? I'm new to the hot rod scene and the truck i bought appears to be built for the 1/8th mile with an overdrive for cruising. But there's a red switch on the shifter and my buddies tell me it's a line lock system for launching the truck (an automatic). How do these tings work? How do I use it? How can i determine if that's actually what it is?
any help would be awesome cause i live in an isolated northern town and my resourses are very limited. That's why I came here.

Check the truck out a bit closer, especially the tranny part. Either that switch is for a brake line lock or a trans brake. We need a bit more info after you check it out. If it a line lock, it's a simple solenoided system to hold front brake preesure to start a burn out or even help hold the car at the line while you ready it for launch. If its a trans brake set up, it holds reverse against first until the light turns green and releases the reverse hold.

As Nitro said

Look under the hood near the master cylinder for a solenoid looking part that has a brake line going into it and out of it. The solenoid is about 3 inches in diameter and 3 or 4 inches long.

The line lock is activated by depressing the brake pedal and then pushing the switch button on the shifter. This button engages the solenoid to hold the pressure in the front brakes. Next, release the brake pedal while keeping the switch depressed. Now you have the front brakes locked up until you release the button. The back brakes unlock when you take your foot off the pedal so you can hold the car from rolling by the front brakes.

If you let off of the button at any time, the front brakes release normally. If you push the button and then push the brake pedal, the front brakes dont work because the solenoid has closed the port.

But then, the button is probably for looks only and isnt connected to anything!!

Please do some checking. Like robot said might be just a dangly little doo-dad that does nothing.

So i found the solenoid... so now is this system for launching (ie. drag racing) or simply to hold the front brake to do a burnout cause i can do that myself.

If the solinoid is in the break line its to hold the front breaks on. If it is working ,push on the break pedal hold the button in let go of the break pedal and the front breaks should hold. After that you can do what you want. I wouldn't trust it for a parking break. But it will save the rear break shoes while doing burn-outs.