Organising files and resources used by a .net project

vb.net vs2003

Where is the best place to put related files eg xml files when developing a project?

They need to be accessible from the development project and also the installed project, so putting them in the solution folder is awkward. I wanted to use the LocalUserAppDataPath but you can’t specify this when adding a file when developing the project, or can you? Can anyone advise me how they have cracked this problem.