Using Inkscape
Inkscape is professional quality vector graphics software which runs on Linux, Mac OS X and Windows desktop computers. It is free, so you can download it, use it from home, then come to class with your work ready to cut or engrave.
Tutorials:
The goal of these tutorials is to present Inkscape in small, easy to consume articles that help you get started with inkscape if you have never used it before. Each simple step has animated GIFs that allow you to see how to do each part.
The first tutorial shows the absolute basics of Inkscape – how to create simple objects such as stars and circles, and the basics of moving, rotating and resizing them. You can skip down to the “Dive into Inkscape (getting started)” section.
The second article introduces the Fill and Stroke dialog for adding some extra colour to your drawings, and also introduces the basics of the gradient tool.
Here is a video that explores Raster (etching) vs. Vector cutting, tracing with Bezier tool, and using text.