If you have technical capabilities in-house you can simply download the
latest version from the web. You will need to have PHP and MySQL
running on the machine where you plan to run the installation from.
Some specialist web hosting companies offer pre-installed Drupal sites as part of their offering. In this case check that you are using the latest version.
If you are employing a web developer to build the site for you, they
will download and set up the latest version of Drupal for you.