To answer your questions...
1. To show the first form again after it is hidden, simply put Form1.Show() under whatever event you want the form to be shown.
2. You must first go to the Project menu, then select [project name]
Properties. Under the Application tab, change the Shutdown mode to "When last form closes". (Note: If this option is grayed out, ensure that "Enable Application Framework" is checked.) Then put Me.Close() where ever you are using Me.Hide(), and the form will now close instead of hiding, without ending your whole program.
Lastly, just one thing I want to add. You should use Application.Exit() when you want to close your program. This will properly end the program no matter which forms are open or how many forms are open, without doing any of the above steps.
Also, are you sure you are using VB.NET 2008? When I tried to open your program, Visual Basic 2008 Express Edition detected it as an older version of VB.NET and made me convert it. It looks very VB.NET 2003 to me.