2003 Nissan Altima Belt was squeaking, now its clicking on

I noticed a squeaky belt about 1 week ago, while the car was moving. I haven't been able to fix it yet, and then I just started hearing a clicking sound, instead of the squeaking. What could this be? I've noticed that once the car has been running for a bit, the clicking stops. I've checked oil, it seems fine. But from a dead start, it clicks pretty load.

Can someone provide a hint as to what's probably going on? Along with a ball park range for repairing the possible problem.

Thanks,
Ryan