sounds like your pads just need to wear into your rotors and then the sound will go away. another possibility, you installed them slightly wrong and they're rubbing in a bad way on the rotors.

as for the other noise, it's due to the humidity in the air condensing on the cold belt/pulleys. once they warm up, the sound will go away (like you said). it could be either that the belt is too loose or too tight. give it a pull and see how much play is in it. if you can pull it more than 1/2", then it's too loose. less than 1/2", and it's too tight.