I use ArcGIS most often but the most simple way is 'my maps' in google maps. If you only want to show loations. I primarily used ArcGIS because that's what I was trained on, but others have mentioned good alternatives. A piece of advice I would give: GIS software has become very user friendly over the years. So much so that a novice can easily create a map that on the surface may appear sharp/valid, but in fact could contain many errors or poor practices. I would recommend reading up on some fundamentals of cartography literature, projections, etc., to be sure your map/figure not only 'looks' good but is 'spatially' accurate and well designed. Many resources out there for this kind of thing. Take advantage. Better to do your homework now, than to send out something less than appropriate and/or repeat work later. Good luck!!! I also recommend QGIS. ArcGIS is a great software but QGIS is open source, so you can use it without any restriction. If there are base maps of your area of interest available you can use them as a layer and them add others layers you want (polygons, points, lines) ArcGIS is one of the good software for producing any kind of map. similar to others answer, you can easily add base map of your study area with good resolution. In that you can add GPS data also in case if you used GPS for coordinate collection. Good luck... Source.