Information about my sources for other GIS uses.
Basemaps edit
National Atlas - For maps in the U.S. this has almost everything you need, including cities, counties, urban areas, roads, railroads, rivers, watersheds, federal lands, and native american lands. For roads the NHPN may be better.
Natural Earth Dataset - An updated version of Vmap0, I plan to start using this as a replacement.
Vector Map 0 - An updated version of the DCW, I use this for most of my basemaps outside the U.S.
Digital Chart of the World (DCW) - For maps outside the U.S. this has country boundaries, cities, roads, and rivers (drainage). Note this is out of date though so use with caution. (no longer available)
SRTM - direct download page - worldwide shaded relief data used for most Wikipedia maps, higher resolution than the GTOPO dataset below.
GTOPO - A public domain source for elevation/shaded relief data for the whole world. For relief you can also use this series on commons
GeoBase - For maps in Canada this has most of your basic information.
Rivers edit
For U.S. rivers use the National Atlas, for Canadian rivers use GeoBase. If you need more detail you can also use the National Hydrography Dataset but it's not as user friendly. The Watershed Boundary Database contains smaller watersheds than those available through the National Atlas and has more up to date area information. Now there is also NHD Plus.
For non U.S. rivers use USGS Hydro1K which has both streams and basin boundaries. It does have a lot of mistakes though so I often use DCW or commercial atlases to check it. WRI is also a nice source to use as a check.
Metro Areas edit
Protected Areas edit
Protected Areas Database for the U.S. only, but is much more detailed than the National Atlas layer.
Railroads (and roads) edit
North American Transportation Atlas includes U.S., Canada, and Mexico
National Transportation Atlas U.S. only, but is more detailed and up to date than the above.
Airports edit
Your software needs to be able to change projections and plot latitude/longitude data from a spreadsheet in order to make these maps. I use the CGIAR world boundaries as a base. Change the projection to Azimuthal equidistant (usually listed under polar projections, may be split into north polar and south polar in which case use the one for the hemisphere your airport is in). Change the center point of the projection to the latitude, longitude coordinates for your airport. Next you need to compile a spreadsheet with your destinations with coordinates for each one and the IATA code if you're going to label it. If you're going to color different airlines different colors you'll need that in there as well. An example I used for Albany is here (excel format). Coordinates can usually be found here in Wikipedia, most airport articles have them, complete with a GeoHack link that will provide them in the decimal degrees format that most GIS programs prefer. Plot and label your destinations in the GIS, labels will likely need to be adjusted by hand to prevent them from overlapping.
Formatting edit
I use ArcGIS for all of my maps. Maps are exported in Postscript (EPS) and converted to PNG format in Photoshop. Finishing touches and lables are often added in Photoshop as well. I have yet to find a way to convert ArcGIS maps to SVG format without the results looking awful, so my apologies to you SVG fanatics out there. If one of you has found a conversion that isn’t too labor intensive I’d be glad to hear it.