An empty project can be created (Project/New). After creating the project, further files can be added by using Open from the menu or toolbar, and then confirming in the subsequent pop-up dialog that they should become part of the project. All file or directory paths are stored relative to the directory containing the project file, which means that only files in the project directory or below can be added.
But a project isn't made up only of files. Bookmarks too are stored, and now one or more configurations can be added to a project. From the Project menu, open the Options dialog. First you have to add a configuration. After that the Commands and Environment fields are enabled and you can now edit them. This feature is useful when working with two compilers, e.g. you can switch between the compiler for your system and another cross compiler. It is also possible to create two configurations each with a different build command: one to generate the debug, the other the release version of your program.