If you can call the insuarance company and file a claim. Best way to go would be a mitigation company. But this is DIY so damn the torpedos!!!
1. You do not need to replace the sub floor. The only instance you will actually need to do this is if the sub floor is actually rotted and soft. Even then you could probably get away with cutting out the rotted section and patching with some Plywood or Advantech.
2. Home Depot sells a Ryobi Moisture Meter. It works just as well and is more user friendly then my $400 Tramex meter that I use on water damage. The Ryobi meter costs about $40. You will need it.
3. Throw a couple of fans and a Dehumidifier in there and let it go. Check your sub floor with the Ryobi meter. You will want between 12% and 15% on the SOFT WOOD SCALE.
4. Any water damage under the sub floor such as the ceiling to the first floor or into a basement would need to addressed also. I would recomend you just rip out any drywall and insulation you come across.
I was lying in bed, looking at the stars, and I wondered, where did my ceiling go?