Dim bgimage As String = ofd.FileName.ToString()
Me.BackgroundImage = New System.Drawing.Bitmap(bgimage)
ofd = OpenFileDialog
You would want to also set the settings for the ofd such as title, filter, initial directory, ect.
As jmcilhinney said, you would simply create a setting in the project's properties and save that setting after the user selects the image or on form close.
My.Settings.setBGImage = bgimage
With that code the setting that I created is named setBGImage
This would be an example of a form load event:
If My.Settings.setBGImage = "" Then
Me.BackgroundImage = New System.Drawing.Bitmap(My.Settings.setBGImage)
Hope that helps!