Hi Steven
hope this is what you are looking for...
create a material to a basic object first, for instance a plane, adjust the material until satisfaction ,than use "Create new master" to create a new master material, apply the master material to other object!
to modify the master material, select the object, open the object's info panel, uncheck "Life material" than open the object's material panel, click the "Reload from master" button, now you can modify the material without affecting the master material, after some adjustment to the material, you can either save a new master material, or use "update master" to update the master material.
Loon