To view the build progress from another computer, provide access to the build log file on the server and navigate to/refresh that file on the client.
One way to prevent a second build from running if another already is would be to add an Exit step at the beginning of the build which builds only if
[vbld_AppIsRunning("Visual Build Professional", False)]
is true
http://www.visualbuild.com/Manual/exitaction.htm
http://www.visualbuild.com/Manual/buildrules.htm
http://www.visualbuild.com/Manual/sysscriptmisc.htm
Another option would be to exit the build if a marker file exists, and create that file at the start if it doesn't exist and delete at the end of the build.
http://www.visualbuild.com/Manual/sysscriptfile.htm
http://www.visualbuild.com/Manual/writefile.htm
http://www.visualbuild.com/Manual/deletefilesaction.htm