I hate to jump in here but after he was on his way I just had to...
Never heard that one before.
Rag, cloth, sack, mesh, Minnie?
Back on topic. Roof Cement and re-enforcing cloth would be the way to seal the seams.
Put down the first layer of roofing. Lay your second run above the first overlapping the first layer the nail thru both layers. and so on UP the roof. Start at the bottom and work your way up.
When you done with that start at the top and work your way down.
Follow what Ed explained in covering the seams, this is called 3 coursing the seam. Cement, cloth cement. Extend the first layer at least and inch or so wider than the cloth you're using that way you'll better cover the cloth with the second layer of cement.
Why start at the top? That way you're not crawling over fresh cement as work across the roof. The fresh stuff will always be above you.
(you will get the cement all over your hands, arms, shirt, pants, shoes, face, and places you'll wonder about later in the day)
That should do it.