Bladerunner,
I use Visio at work... it's as close as you can get to true scale without using AutoCAD or similar. I use it a LOT to do my designs. It has provisions for dimension objects too. 8-D
Here is a sample I did that was a screen capture.
Again... when you print directly from Visio, it uses the printer settings to get the scale correct (okay... 99% correct).
Hope that helps...