Look you do not have any routes "/static_pages/about"
so you got error
Routing Error
No route matches [GET] "/static_pages/about"
As per your routes for about page /about
should be the url
http://localhost:300/about
http://localhost:300/contact
http://localhost:300/help
It will acutally call your static_pages
controller and about
action of that controller
and from url helper of rails routes you get
For About:
about_path
or about_url
should be used
For contact
contact_path
or contact_url
For help
help_path
or help_url