If your idle is "rough" (i.e. heavy vibration/shaking) rather than just "hunting" (i.e. bouncing RPM levels), then your problem may be an ignition coil rather than an MAF. They can cause similar symptoms (stuttering idle and delayed throttle response), but the ignition coil failure symptoms are much more pronounced and will cause a rough idle and possibly stalling.

You probably need a new MAF anyways, but if that doesn't fix the problem then check the ignition coil packs, which are attached to the top of 3 of the spark plugs (6 cyl). The ignition coils are very easily switched out (15 minute job) and cost about $65/each. While you're changing your coils you may also want to swap in a new set of spark plug wires ($60) and possibly spark plugs if they're old ($1-$3/each). My theory is that its best to swap out everything while you're in there to minimize the work later.

Hope this helps.