Forget about hiring a programmer or programmers to develop an entire website and tailor it to your specifications. Over the last few years developers have done this over and over again. From this comes a variety different approaches and implementations to managing website content. Some is commercial like Microsoft Sharepoint and others open-source, freely downloadable and modifiable for your purpose. For a new installation, all that is required is one programmer to install and configure a pre-packaged Content Management System (CMS) such that the web interface works. Once the customer is able to login to the backend to manage their site, public front-page content can be managed, organized, categorized, logged, permissioned, sold, you get the idea. The customer can take over and customize their own website - entering and organizing content, processing orders or using whatever other built in tools. Or better, paying someone who isn't a programmer to manage this task in effect minimizing the administrative effort that goes into running a high-traffic website with lots of products and updates.
A ton of website code is pre-written, don't waste time and utilize it. This means you can put the files on your website, enter in your settings, create and maintain an entire data-driven website using a browser. It sure beats paying someone to build something from scratch with no documentation that only they can fix. You will need a database as part of your website hosting, and that is the task of the solution developer to connect. Some CMS packages are only designed to be used with either Microsoft SQL or MySql and not both. Design is important and depends on what your site will do. Luckily, there are eSolution professionals who can help.
In an advanced CMS system you can design complex categorizations to organize and display all your data. Some work goes into making it look the way you want, such as logos, colors, and where your boxes and menus are. The data, can be added by users or administrators or could be imported from an existing database or CSV file. In a recent project, I migrated a Coldfusion website built from scratch using a MS SQL database, to a PHP CMS application (called ZenCart) that uses a MySql database. Required was preserving the existing products, descriptions and prices - added were the many features included in the ZenCart CMS by default. By default, the package includes SSL functionality, an inventory system, more options for products, and real-world shipping and payment modules all configurable using the backend login.