Only a few software packages can create graphics to be embossed on a standard braille embosser. Two of them are by Duxbury:
TGD Pro: I have seen its work but don't know much about the software itself because it is not free and most tactile graphic artists, at least the ones I know, don't recommend it. Click this link to learn more about TGD Pro by visiting the Duxbury website.
QuickTac: A free software package by Duxbury lets you draw simple line graphs and geometric figures and import them to a Duxbury file and emboss at once. The newer version has some very impressive enhancements in functionality. Click this link to learn more about QuickTac by visiting the Duxbury website.
Another freeware program is called Braille Paint (BrlPaint), developed by an Eastern European guy. It is similar to QuickTac in functionality. Click this link to visit the BrlPaint download page.
All the programs mentioned can create drawings that can be embossed directly. The resolution is pretty low and everything is assembled by braille dots, which is generally not recommended, but good enough for quick mobility map or classroom activity, etc.