The central struture of TFS is to have local copies of a ASP.NET project on a developers machine, while having the “quality controlled” pool of code in a centralized location. The way to do that is after logging onto the TFS server through the Visual Studio client you map a local folder that then syncs with the TFS server when you checkin or check out code.
Here’s the instructions from MSFT for doing so:
How to: Create a Mapped Workspace
Create a workspace so that you can perform Team Foundation version control commands on your computer. A workspaceincludes client-side folders on the local disk that are mapped to version-controlled folders on the Team Foundation version control server. For more information about how to create a workspace from the command-line, see How to: Create a Workspace from the Command-Line.
To see all the workspaces you have already created for your account, use the tf workspaces command. For more information, see Workspaces Command.
The following procedures describe how to create a workspace for Team Foundation version controlled-items by using Source Control Explorer.
To perform these procedures, you must have the permissions for Create a workspace or Administer workspaces set to Allow. For more information, see Team Foundation Server Permissions.
To create a mapped workspace, perform the following procedures: