There are two ways to go about the MAF, Draw Through or Blow Through.
If you're running Draw Through, that's before the turbo. If this is the case, you want to run the MAF at least 18" from the turbo, since turbo causes a turbulence in the maf.
If you're running Blow Through, you want to put the MAF after the blow off valve. It's probably not a good idea to put it on the hot side because of the heat. If you running it like this, try to get the MAF to be at least 12" from the throttle plate.