Wainscoting - Distinctive Wall Paneling

Hello Tim

I am in process of decorating my dining room. The ceiling and walls have been painted,and now I am putting up striped wallpaper from the bottom to half way up the walls surrounded with a chair rail on all four walls.

Question: I've never wallpapered before. Where do I start the striped wallpaper? Near a window, the doorway and do you lose a lot of wallpaper with stripes?

Thank you.
SP