I wouldn't have user accounts on a web server, and I certainly wouldn't make their home directory htdocs, unless you want all of them mucking about with your website.
I use CentOS, and instead of htdocs being my web root directory, /var/www/html is where all my "stuff" goes.
Beneath the web root directory, for a small website, I would probably only have two subdirectories: docs and images. In docs I'd place .PDF files and the like. In images I'd put all my images - logos, photographs, bits of images needed for CSS, and so forth.
Some folks like having a css directory with assorted CSS files in it, but I put all of my CSS into one monster file in the root directory (web root - htdocs for you, /var/www/html for me) and load it once and be done with it.
You could also make subdirectories for the major areas of your website. For example, if your website is about pets, you might have subdirectories for dogs, cats, fish, birds, reptiles. Inside each of those subdirectories you could put an index.htm (or index.html or index.php or similar) file, so that visitors to your website would just need to type in "http://my.website/dogs" to get to the section about dogs.
OR if your website is small enough that you only need one page for dogs, don't bother with the subdirectories, and let your users browse to
http://my.website/dogs.html or similar. Even if there are 2 or 3 sub-pages to the dogs page, you could leave everything in htdocs and call the pages dogs.html, dog_breeds.html, dog_diet.html, dog_grooming.html and so on.
Basically you just need to think about what you want to accomplish with your site, and what is the most logical and easy to maintain way to go about it. Whatever you decide on, BE CONSISTENT. Otherwise you're getting yourself into a maintenance nightmare on down the road.