Imagine a grid or draw one if you can't imagine one. Let's say it's 2 by 3, but it could be larger or smaller. Each grid square abstractly represents a distinct area in your town, and the grids abstractly represent the layout of those areas in your town, meaning the relative placement of one area to another area, not the shape or size, or the scale. If any of the areas of town being represented by the grids are particularly big or small, notate it in the grid as you go.
Name each area of town and label your grids. Example: North End, West End, Center Square, Old Town, etc. They don't need to be the official names of areas of town, they could be the informal names given to them by folks in town, or names you give them for the purposes of organizing town. You may want to try to come up with names that describe what primarily is there, like residential area or business district.
In each grid, list major locations. Example, City Hall is the name of an area, and so it's also the name of a grid space. It includes all the government buildings such as the City Hall, the mayoral manor, Prisons, Courthouse, gallows, and stockade. It also has a job board or bulletin board for odd jobs and news, and official proclamations. Maybe there's a mail courier station. It might even have an armory or barracks for the town militia. You can also list important NPCs, products or services associated with each location.
Finally, scale. Instead of a bar or line marked with a distance in feet, yards, or miles, we'll do something simpler and more practical. The scale will be walking time, and the walking time for this town will be 1/4 hour. That's how much time it takes for the player characters to walk anywhere within one area. If the players want to walk from one area to another, add another 1/4 hour for every area they pass through.
