Website directory structure advice needed - web

Question

I am only used to developing a website that has like 4 to 6 pages (index, about, gallery...)
Currently working on a random project, basically building a large website. It will be using multiple subdomains and maybe up to 2 different CMSs
So before I start building on, I heard it is a good practice to have only one html file (index) per sub directory. Is it a good practice?
My current directory structure:
/main directory
/css
/img
/js
So if I were to create an about page I should add a new folder pages to the main directory and also for all other folders: css, img, js and have all relevant files there?
Example:
/pages
/about
Also if I start using a sub domain, should I create those (as shown above) folders for that specific sub domain?
There are other related question on here, however it does not fully answer my questions so I posting a new question.

Answer 1

There's no specific reason to keep each HTML file in its own directory. It just depends how you want the URLs to appear. You can just as easily link to
http://myapp.example.com/listing.html
as to
http://myapp.example.com/listing/
but the former will refer to a page explicitly, whereas the latter is an implicit call for index.html in the listing directory. Either should work, so it's up to you to determine what you want.
You aren't likely to see much efficiency differences in either solution until you are up in the thousands of pages.
For subdomains it is simplest to keep each domain separate, as there is no specific reason that a subdomain even runs on the same server (it's an entirely different web site). If both domains do run on the same server then you can play tricks with symbolic links to embed the same content into multiple subdomains, but this is already getting a bit too tricksy to scale well for simple static content.