If you want to emulate the behavior of an editor like Notepad, you might want to turn on visual line mode. While setting word-wrap will cause line wrapping at word boundaries, any action you take on a line (e.g., moving up/down or killing) will still respect the newline character. Visual line mode will treat each display line as though it had a newline at the end.
(visual-line-mode t)
Line to add in .emacs file:
(global-visual-line-mode t)