I've used both of these programs, and each has their uses...
http://forums.civfanatics.com/showthread.php?t=141622
http://forums.civfanatics.com/showthread.php?t=144414
I usually get a digitialized map of the area I'm interested in, and crop it to the dimensions I want.
I try to make maps so that evey 10 pixels represents a tile. For example, an 80x100 map would be made from a digital 800x1000 pixel map. Then I set the grid on my paint program to match. Ktwsolls program can directly use digital maps so tracing out the map is easy with his. With Mapview, you need to flip the digital map upside down. I then outline everything in plains or grassland to create the land masses. With map view, just read the pixel coordinates of the upside down map, and fill in the tiles with the same coordinates.
I do a lot of cutting and pasting of many many maps... political, terrain, etc over my original map to fill in things like rivers, mountains, etc.
I've been using CIA world, and Europe digital map as my base landform and big river map, then overlaying it with various other maps (lots of resizing and rotating involved there) to get all the features I want. There are a lot of historical and geographic maps out there.
I never use worldbuilder directly.
If you need specifics, just ask.
PS I should mention Ktwsol's program no longer, for whatever reason, works on my computer, so I've recently been using Mapview, exclusively... it's ok.