In addition to the advice to check out Mike's site, remember that the Effort
Driven setting only has an effect when you're adding or taking away bodies
from the task resource assignment. If I have a task and already have one or
more resources assigned to it, the effort driven setting will control what
happens if I add another resource. If it's effort driven, the task duration
will shrink but the total man-hours stays the same. If it's non-effort
driven, the duration will stay the same but the total man-hours of work
required will go up. And the opposite occurs if I'm taking away resources
instead of adding them.
Task type controls what happens when you edit existing resource assignments
without adding to or taking away from the actual number of resources
assigned. It controls which one of the three terms in the resource
equation, Work=Duration*Units, you're want Project to hold constant when you
change one of the other two remaining terms for one or more of the resources
who are assigned.
