GIS = geographic information systems?
I used AutoCAD in my first drafting class in college ~8 years ago, before switching to 3D modeling software like ProEngineer (now Creo, I think), AutoDesk Inventor, and Google Sketchup. I didn't find the basics difficult, as it was pretty intuitive, and I would *guess* that it has tutorials like Inventor did to help you learn all the tools. There's also a pretty great online community. Could you ask to see and spend an hour playing with the software before you commit? Also depends on the features you'd need and your ability to teach yourself...