MySQL is not an out-of-the-box ecommerce package. It's a tool with which you can create an ecommerce solution, but it would take a lot of work.
Here's an analogy: you have an automobile and some part in the engine is worn out. You want to fabricate a replacement for the worn out part, and you have a metal lathe (http://en.wikipedia.org/wiki/Metal_lathe). To create that engine part, you'd need to have other things: the specifications for the engine part, some raw metal of the right type, a workshop with other tools, and finally a lot of knowledge and experience about how to use the metal lathe safely and effectively.
Likewise MySQL is one of the tools you'd use to create an ecommerce solution, but you'd need to use it in cooperation with other software tools, like programming languages, a web server, an SSL certificate, etc.
There are several books about how to do this, for example, "Beginning PHP 5 and MySQL E-Commerce: From Novice to Professional" by Christian Darie, Mihai Bucica.
http://www.amazon.com/gp/product/1590593928/ (see demo at
http://cristian.nexcess.net/)
You might look for ecommerce solutions someone else has written, that happen to use MySQL. There are many. Here is a directory of products:
http://php.resourceindex.com/Complete_Scripts/Shopping_Carts/
EDIT: I forgot to mention that the most important part of the process is to decide what parts of your business you want to try to automate, and to be able to describe every detail of this automation. Do this before implementing the software system, or even before choosing what tool you want to use.
Edited 1 time(s). Last edit at 08/03/2006 10:22AM by Bill Karwin.