You should make an airtight seal between the work area and the other areas of the house. A good choice of tape for this step is the blue masking tape from 3M, which can be used on painted surfaces, wallpaper, or woodwork, without damaging the surface when removed. All workers need protective gear, since demolition is a dirty, nasty job. The most important item is breathing protection. If any plaster removal is involved, you need a respirator with a particulate filter.
Dust masks are next to worthless.
If any plaster removal is involved, I highly recommend a Tyvek body suit with integrated hood, to be worn over your normal working clothes. The hood very effectively keeps plaster chunks from falling down the back of your neck and keeps the lime-rich plaster dust from caking in your hair. Lastly, you need a good pair of heavy-duty gloves. I find that heavy leather work gloves give some protection against nails and other pointy objects. Now you're ready to begin.