I use AutoCAD and I have a few friends that use Corel Draw. I tried to convert them to AutoCAD till I saw how well it works. Some will tell you Corel doesn't work but they're wrong. I went to get a demo on a laser last month and they use Corel as well as their clients.
I'm starting to play with Rhino and it seems to be a combination of Corel and AutoCAD.
With any of them you have to import your plans rather it's a tiff, jpeg, or what ever and then draw over it.