Thanks for the links, that clears thing up a bit. I can see that the page you referred to is an html page. This will not work with the restrictions. In order to restrict a page it must be a .php page type and it must have the access rule code at the top of the page.
You can convert your html pages into php pages by simply changing the file extension from html to php. All html code is perfectly valid in a php document, you just have the ability to add in php code to these pages. Once you have renamed the pages and updated the links for them you can put the access restriction code at the top of the page to stop users from accessing them without being logged in first.