I want to make a quadcopter for my final year project and I am willing to use DC motors as the four rotors of the quadcopter. Can any one guide me about the ratings for proper motor selection for my job.
You'll need to use brushless (as opposed to brushed) motors for a quadcopter:
The motor goes hand in hand with the propellers, so you have to make sure they are compatible for your application, as you'll need to generate enough thrust to get it to fly (so it will depend on the weight):
If you want to build a really cheap but great flying quadcopter, check out coreless micro motors: http://www.rcgroups.com/forums/showthread.php?t=2009496