The following provides a set of links to various ArcGIS tutorials that are available online. For more ArcGIS help, please refer to ESRI ArcGIS Help Library The following provides a set of links to various ArcGIS tutorials that are available online. For more ArcGIS help, please refer to (ArcGIS Resource Center): First assemble your coordinates in tabular format (.ccv or .dbf). Degree-minute-second (DMS) coordinates should be stored as a single string in one field. Latitude is first followed by longitude separated by spaces (e.g., 43 33 36.60 80 15 53.72). If the location is west of the Prime Meridian, the longitude must be expressed as a negative value in all the Degree-minute-second numbers (e.g., -80 -15 -53.72). DEM files are created in a variety of formats (.dem, .flt, .asc, .txt), which require processing before use with GIS software. The following tutorial outlines steps to convert, project and merge DEM data for use in ArcGIS. DEM is a raster representation of a continuous surface (i.e., the surface of the earth) where each cell in the raster dataset represents surface elevation. Patterns that are not readily apparent in the DEM can be derived from it, such as shaded relief, contours, slope, aspect, hillshade, viewshed, curvature and cut/fill. In ArcGIS, this can be completed by using the Surface Analysis tools provided in the Spatial Analyst toolbar. Source.