Could someone be so kind as to sketch on this image where they suggest i put vents?

I seem to get conflicting advice whether one vent is enough or if each appliance (shower, lav, water closet) needs its own vent.

thx


https://dl.dropbox.com/u/79088836/plumbing05092012_00000.pdf"]https://dl.dropbox.com/u/79088836/plumbing05092012_00000.pdf