Day 2 - Map.
As far as I'm concerned, maps for roleplaying games, whether they show a country, a local map, the interior of a catacomb, whatever, are one of the lesser evils that can be found in roleplaying games. Part of the reason for this is that while I have a good grasp of geography and the science behind how geographical features arise (though in fantasy games, magical events and climate can account for many deviations and unnatural terrains), my mapmaking and drawing skills are pathetically woeful. I tend to do hand-drawn maps for my games, particularly the fantasy ones, and don't use computer mapping programs since, to be honest, I don't know how to use them and don't really want to buy them. And I'm not about to spend money to have a good gaming mapmaker create one for me.
Of course, maps serve several purposes, primarily for use in showing the game world, the country or region the player characters find themselves in, and give the GM a good idea of what their game world (even if only a portion of it) is like. And maps are useful to GMs in scenarios, to show the specific terrain of the adventure, to show the interior of structures, underground areas, and the like for the adventure. And then there's switching to a battle map or tactical display that gets the players' juices flowing and makes for a truly immersive activity in rpgs.
Something else to consider about game maps is this: Very often the map of the game world but more usually the map of a region of the game world (such as a country, a barony, a set of islands, whatever) will inspire me (the GM) with a feature present or a specific location name for a scenario based on that specific element. That said, the real trick with game maps is the sheer scope of them. Very often, GMs encounter a map and try to do too much with it. Or when they are drawing their own maps for their game world, they tend to map out too much and lose their focus on what they're trying to do. My usual advice for starting GMs is this: Map out the local area in which the first few adventures are going to take place. Have an idea of how the map you're going to create connects to another map. Scribble a few notes about other areas off the map that may be of interest to you for the future, or where the player characters might come from originally. That sort of thing. Don't go hog wild and crazy with mapping out a large area to start with.
Finally, there's this to consider. Alfred Korzybski (who shares my birthday interestingly) once said that "The map is not the territory. The only usefulness of a map depends on similarity of structure between the empirical world and the map." When running a game, remember not to worry about the accuracy of the maps. This applies to both the map you have and the map you must provide the player characters or allow the players to draw. After all, most maps aren't accurate. There are always dangers and places that haven't been mapped yet.