Dimensions are one of the most well defined areas of AutoCAD and one of the most misunderstood. Misunderstood at the base level. Not many know all of the variables that need to be defined. If you think that DIMS are simple, just do a search in your AutoCAD help file for “dim” and look at all the topics that come up. There are over 80 individual dimension variables with more being added to just about every release. That is about 10% of the variables that are in AutoCAD.
Settings fro dimensions should be set in your template files. No need to have someone set them up every time they need to have a dimension. So setting them once is best.
When setting up the standard, you need to go through every dimension variable to verify that each is set as you like it. You can use the dialog boxes.
Here is a good tutorial on setting up Dimensions  by Art Whitton, Chester, NE