We are going to use Vcarve software and although its not free, it specifically designed for making signs, and is more "Art friendly" than prodesktop which is more for engineering projects.
Vcarve has a trial version, to play with but it may not let you generate a "G code" with out paying, which is ok as unless you own or have access to a CNC router or mill you wont need to generate a G code, you can just have a play with it and decide if you like it or not.
If you missed the other projects in this series they are here are here
Digital Manufacturing - project one Key tag
Digital Manufacturing - project two desk name plate
Digital Manufacturing - project three 3D printed box
Digital Manufacturing - project four laser cut box
As computer tutorials don't translate to text very well, for this series of instructables most of the info is in the photos. So click on the first photo and use the arrow keys on your key board to go to the next photo. The boxes in the photos show the location of the icons and have have text in them when you hover the mouse on them.