One possible way is to put an index.html file into your web-directlry..with some simple message saying "under construction" or "coming soon"
any visitor coming to your site will get that page.
the rest of your pages should be available to you as long as you know the links to those pages.
When you are ready to launch, just delete the index.html and replace with whatever your home-page is.
there are other ways, but this would be a simple quick solution.