There are many ways to approach mapping.
The GC has ArcGIS installed on its public workstations. There is also an open source analog that you can install on your computer called QGIS. However both require a steep learning curve and might be toocomplicated for your purposes. Other approaches such as using a Wordpress plugin such as MapMaker with Google Maps API or Open Street Maps might be just as useful and requires a lot less frontend investment rather than learning a new complicated platform.
Here is a more comprehensive guide to help inform your decision.
Make an appointment with Stephen (sklein@gc.cuny.edu) or Steve (szweibel@gc.cuny.edu) to explore the best path toward your mapping needs.
Meanwhile, here is a useful guide that might get you started. Also, Frank Donnelly, a Baruch College librarian, occasionally gives classes so watch this page.