rear brake/suspension squeal/creak?!

[00 scrub]

I am having a problem with my rear suspension and/or braking system. It first noticed the problem a while back, whenever I backed out of my garage and onto my driveway my rear brakes would emit a light squeel as I slowed to a stop on my driveway. This was in reverse gear. But this also ocassionally showed up while I stopped at stop signs, but not all the time. Another odd sound came from my drivers(I think) side rear wheel. I was in a parking lot and it woudl emit a VERY loud screetch/squeel as soon as I got moving (about a second or a second and a half after I realeased my clutch). This only lasted for a few minutes, and when I came back and drove home the loud squeel was gone. What is this? and Why is it happeneing? I am also getting a creaking noise from my handbrake whenever I park it. I don't remember when this noise started, but whenever I park and pull up my handbrake and get out of my car the rear brakes (I'm thinking the parking brake) will creak. If I push the car lightly it creaks. This has me worrying that my e-brake is about to go, so I always keep my car in gear now when I park it. Why is this problem happening. I really have to take my car to a Toyota dealer. I have a 2001 GT-S with 13k on the odo, and my only mod is an AEM CAI.
thanks

[YOshi31]

take it to the dealer and have it cheked out ASAP that sounds like a bad thing and brakes are everything about the car if it goes thats good but if it cant stop whats the use and you sould always keep your car in gear when parked 1st if park normally and reverse if back in a spot so the car wont go anyowhere and so that if your p brake is not working it wont go the direction you dont want it too and if someone tries to tow it they have to put it on a bed and that takes a long time and you might be able to save the car if you have too