To get the latest version of all the files and the new files that are in a module (or project in JCVS terminology) that you already have checked out you have to Update. This can me done for the whole module, one file or multiple files.
Updating the whole module
Updating the one or more files
After you have updated the latest version will be in your working directory. If you had prior edited one of the files in your working directory it will not be updated. The icon for that file will be red. You will need to either commit your changes, assuming you have permission, or delete the file and allow JCVS to refetch it on an update.