To create new data on the map or updating an existing one, one of the applications that can be effectively used is Quantum GIS. It enables you to have the Geographic Information System (GIS), i.e., the access to all the information about the existing aspects of the maps.
Raster direct viewing, vector projection, interactive exploration of places with maps, editing and reviewing is some of the options that this application provides for you. Using these features, you can easily modify the map according to the new information you have.
Different types of maps are supported by this application, including Post GIS or SpatiaLite. You can edit each of these formats by adding in labeling or bookmarking some particular place. Even the vector features of the map can be adjusted too.
One of the limitations is that the interface is a bit crowded, which makes it difficult for the beginners of this application to find the right tool for a specific need. However, after you get used to its features and interface, Quantum GIS is a pretty nice application to use that has the solution for all your mapping needs.
Quantum GIS comes with great features and functionalities to equip you with all the tools necessary to edit or create the maps according to your needs.