Error handling in functions? how should I do it?

[MrPolite]

what's the proper way of doing error handling in a function? This is what I usually do:

Public Shared Sub ResizeImage(ByVal srcPath As String, ByVal destPath As String...
        Dim srcImage As Image
        Try
            srcImage = Image.FromFile(srcPath)
        Catch ex As Exception
            Throw New ArgumentException("Error opening the source image", "srcPath", ex)
        End Try
        srcImage.Dispose()
    End Sub

should I just let the code throw an exception by itself? or is it better to make a new exception like that?