Whenever I turn the car on, there is a REAL high pitched squealing noise. After driving for a second, or warming it up for a lengthy amount of time, it goes away (and in 3rd gear (automatic). But at night when I have the lights on, it almost always goes. And when I stop completely and start going again, it starts right back up.

My Dad said alternator bearing? Someone said belt. I dont know. Any insight?

Plus I broke the back window (vinyl-ish) on it, whats a good replacement?

It's more than likely just your alt belt. They have to be really really tight on our cars. Use a prybar between the alt and the block to tighten it up. This is a real common problem with our cars. There is a chance it could be a bad alt or timing belt tensioner or even a water pump, but more than likely your belt may look tight, but it's not tight enough.

But at night when I have the lights on, it almost always goes. And when I stop completely and start going again, it starts right back up.

My Dad said alternator bearing? Someone said belt. I dont know. Any insight?

Plus I broke the back window (vinyl-ish) on it, whats a good replacement?
Junkyard for the back window........Squeeling.....Your Alt belt is worn or loose. Try this: start the car and let it sit (In Park) and idle and warm up until the belt stops squeeling. If it wont stop squeeling, rev the engine up a couple of times until it does. Now, while still sitting in park, turn the headlights and blower motor ON......The belt should squeel again since you just put a load on the alternator....If it does, the belt is worn or loose.

If your going to replace the alt belt.....DONT buy the one made by Kelly/Springfield! I've had 1 break in less than a year and another that I took off the car because it squeeled bad....even when tight and the pulley's clean! I Use Goodyear Gatorback or Dayco belts now......Zero problems with Both of them!.....You can get them at Advanced auto parts, Schucks, Cragen etc......Link below.

Goodyear and Dayco Belts (http://www.partsamerica.com/ProductList.aspx?PartType=1063&PTSet=A&SearchFor=Serpentine%20Belts)

I have also had good luck with NAPA belts and our cars.