Suggest brake pads? (or something to fix the squeal)
 

So, I have this DiamondBack Sorrento. Pretty happy with it, except the brakes are the loudest thing I've ever heard. I'm pretty sure the entire mountain heard them coming. Terrible squeal.
It current has "Promax 260" brake pads on them. Not sure if they're bad pads or if something else is going on.

Any recommendations?

I live in Tennessee, so wet conditions are a normal thing.

Make sure your rims are free of oxidation. And make sure your brake pads are properly aligned and toed. If those don't help, I've had success with Kool-Stop brake pads on all my bikes.

+1 What he said. Add to that pads don't have any metal or sand embedded. Some Kool-Stop pads have squeegee-like leading edge to scrub off the rim before the nose of the pad engages very much

Alrighty. Thanks for the tips.
I've already cleaned the pads/rims (aluminum so no rust). I also adjusted the toe angle, incase that was a bit off. I'll try to test it today and see how that goes.
If that doesn't work out I'm looking into the Kool-Stop pads. I actually had my eyes on those already.

Aluminum does oxidize. The normal, molecular layer of oxide which forms on bare aluminum is fine. But with surface wear from brake pad rubbing, coupled with moisture and dirt; an uneven layer of oxide can form, which contributes to the problem you are describing.

The bike is only about 2 weeks old, so it's definitely not oxidation.

I just wanted to post an update. I have tried toe adjustment, cleaning, etc. I have even tried new brake pads (jagwire) and I'm still getting the squeal. Anyone else have any ideas?

Maybe take it back to the bike shop you bought it from?

The will probably show you why it makes the noise and you'll learn something, and for free!

That would have been my first response, but the shop is about an hour and a half away from where I am. It's quite the drive.

One thing I can add, the rims are painted black, but the paint is quickly wearing off. Cold the paint possibly be causing the noise?

Look at the brake pads. Do they have gunk on them? If so, that is the problem. I use red brake pads so I can see the crud. I just went through this with a bike I hadn't ridden for a few months. Squealed like crazy, so I removed the wheel from the bike and used a green scrubby with that nasty smelling Simple Green. Rinsed a number of times. Cleaned and scrubbed the brake pads too. Had to do this again after a day of riding and then the squealing stopped. Aluminum oxidizes really fast, like seconds. But it seems if I keep riding the bike at least once a week, I am good to go. If the 'paint' (probably anodized) is wearing off, that is probably not helping. Keep riding and cleaning and of course make sure the toe is correct on the pads. The Park Tool site has good info for that. Good luck.

Make sure wheel bearings and head bearings do not have excess play, meaning 0.