How would you get an order for someone to move somewhere, then after the person has finished that order, he continues onto the next one.

For example
Mob 1, is given the order to move to tag1.
After he finishes that, he moves to tag2.
And so on.

Anyone have some ideas on how to do this?
A simple list of turf waypoints should do the trick. Move toward the first turf in the list until the mob reaches it (or gets within acceptable range of the target, if the way is blocked), then remove that turf from the list and start moving toward the next turf (which is now first in the list).

To make a patrolling mob, you could use the same implimentation, but after removing the turf you'd add it back to the end of the list.

For the actual movement routines, I highly recommend Daedron's implimentation of the A* algorithm in his Pathfinding library.