Audio Systems: Car stero wires, factory speakers, car stero

Question
I recently bought 2 New Alpine type R 5 1/4 Speakers.I have cut off the end of my factory wire, and am trying to hook it up to my speaker but how? They have funny square shaped things on the speakers like where u would hook up the speaker, but how do i know which side is + and which is - on the speaker? And how do I know which wire is + and which is -  one is colored and one is colored with another color stripe. Please help me I'd be sooooo greatful!

Answer
If you have a good ear you can tell weather they are hooked up right.
I'm assuming these are going into the front doors and you are keeping your old factory speakers in the rear?  If so then just connect the wires to the left front speaker and dont worry about weather you get the plus or minus right at this point and loosly install it in the door.  put on a cd with very plain vocals and not alot of background music or backup singing etc and not alot of processing in the vocals like enya or something. country should work well. Use the balance of the cd player to push all the sound to the left side. sit in the car as close as you can to the point where your left ear is pointing towards the front speaker and your right ear is pointing towards the rear speaker and they are as close to the same distance to you.
If you got the plus and minus correct the vocals will apear to be "in your head" and not eminating from either speaker.  if it sounds like the vocals are coming out of both speakers switch the wires and listen again, it should now sound like its "in your head".
Once you get the front left working properly do the same test for the front right.  then use the fade control to push the sound to only the front speakers and set the balance in the middle.  position yourself right between the 2 front speakers, left ear facing left front, right ear facing right front. and listen again.  Concentrate only on the lead vocalist since the rest of the music can come from anywhere but the lead vocalist should again sound "in your head" if you've done it right.
GOOD LUCK!