If other developers want to start using a solution from the repository, they must first checkout the solution from the repository. This process will bring the solution over to their local workspace and link it with the repository so that the developer can now send and receive changes to/from other developers.
If you are checking out into a workspace being used for other solutions, you most likely already have a project already named resources in it. Checking out a project with the same name will ask if you want to overwrite it. You want to use the SVN version with the current project, so you should overwrite it.
This is one reason it is best practice to have only one resource project per workspace. Any solutions (projects) using the same resource project can also be in the same workspace, such as the case with the main solution and any modules connected to it.