Dimensions missing

[LHarv]

When I add a dimension no arrows appear and the dimension does not show. Also, I am having trouble changing the cursor position display to not be in mm.

[andrew]

When I add a dimension no arrows appear and the dimension does not show.

Most likely they are too small. See also FAQ at:
http://www.ribbonsoft.com/qcad_doc_faq.html#11

Also, I am having trouble changing the cursor position display to not be in mm.

You can set up the drawing unit in the drawing preferences: Menu 'Edit' - 'Current drawing preferences'. The coordinate display is in the same unit as your drawing.