Do consider very seriously before making up your mind. Like the others have said, there are many important things to take care of. Most important is vaccination. Then you need to settle medical care. You'll want to get anti-malaria pills etc..
Most of these places don't have power, you aren't going to be bringing a generator so consider how you'll get around to doing things at night.
Even communications can be a problem. Don't expect your cellphone to work nor any working telephones available.
I've volunteered for my unit to go in the next wave (probably to Andaman Islands) to help out. We're better settled than the average joe since our immunisation and anti-malaria pills etc will be settled. We also have our own power generators and vehicles (in addition to the heavy machinery we'll be using to build shelters and move debris). We also have our peacekeeping engineers who can (given time) build shelters for us but you may have to rely on just a small tent.
The first wave is leaving for Aceh and even then, the situation there isn't very friendly. There are TNI soldiers and our own forces to help with our security. But if you go there, who's going to protect you?
So do consider before you decide to go and help out. Your expenses can also escalate. Buying a good torchlight and batteries, female essentials, charcoal pills + misc. medication, disposable underwear, foodstuff, cooking accessories (bunsen burner or solid fuel) etc.. And there's safety concerns, your well-being (who'll provide medical aid), shelter, communications... You should seriously discuss with your family before making up your mind.