Alternators

I think my alternator just went out on my 98 GTi Vr6. Is there an easy way to find out if that is what it is? The only way I can drive my car right now is if I jump or push start it. Once I turn it off, it will not start again without jumping it again. This means the alternator is not recharging the battery, right? Could this problem be because I race it too much? Or do they normally go bad in 7 yrs or so? And when replacing it, should I just get the oem part or is there something more suitable for street racing? Also, are there any special tools needed to replace it? And about how much should I expect to pay for one, new, or rebuilt? And where is a good place to buy it from? I live in the chicago area, if that matters...

Take a volt-meter and test the battery voltage when the car is running. IF its under 13.0volts than its a bad alternator. Get a reman unit from vw. also replace the battery because its problably shot too. and get a new serp belt because you have to take it off anyway to replace the alternator.

Are there any special tools needed, and hoe long does it take to replace?