The simplest way to get the module is to check it out at github. From the command line on your computer. Use the command
git clone https://github.com/econjobmarket/drupal_6_module econjobmarket
to create a new subdirectory called econjobmarket where the code for the module will be stored. Later you can run the command
from within that directory to update all the files with any changes.
If you simply want to browse the files included in the module, use your web browser and go to
https://github.com/econjobmarket/drupal_6_module. You can copy the files to your computer from there if you want.
Now go to your drupal installation directory. The default install on centos puts drupal in /usr/share/drupal6. The installation directory has a subdirectory called sites. Normally, the sites directory will have a subdirectory called 'all', which will have further subdirectories called modules and themes. If you don't have the path sites/all/modules already you can create it. Then move the directory 'econjobmarket' that you created above into sites/all/modules. You should then be able to enable the module in drupal.
The module creates two new permissions 'read candidate info' and 'recruiting committee' that you can use if you have drupal users who you don't want to see your application data. It also creates a bunch of tables in your drupal database. You can remove these later by uninstalling the module if you want.
You need to explicitly allow users to view the application data by going to admin -> users -> permissions in drupal and enabling these for some users. If you have drupal users already, you should probably create two new roles 'read applications' and 'recruiting committee', assign users to these roles as you see fit, then provide each of these roles separate access to the application data.
The next step is to get your data. For this to work, you have to setup your backend database. You have to know your username and password and the name of your database. You can find this stuff by going to the setup link on the left sidebar of this page. You will need to login to see your setup information.
Once you know your username, password and database name, go back to the directory where you saved the the module files - either the original one, or the one under your drupal installation. In that directory you will find a script called 'update_cron.php' and a file called 'passwords_from_install.php'. You need to copy his latter file to passwords.php then edit it. Open it up in a text editor and fill in your username, password and database on the ejm backend server.
You also need to provide the username and password for your local mysql database (the one where all your drupal tables are stored). If you don't know what these are, you can read them in the drupal settings.php file for your site. This is in a folder like /usr/share/drupal/sites/nameofyoursite. The drupal installation directory could be different on your machine.
Now make the script update_cron.php executable and run it. It is a php script which has the linux path to php hard coded into it. You will probably need to change this if you are running windows or mac. The script requires the php-curl library and fetches data over http. If you run this script in the middle of recruiting season, you may have a few thousand pdf files to download, so the script will take some time (over an hour) to complete. When you refresh the files next time it will be much quicker.
If you want to experiment with the data or write your own download script, then you should follow the directions given in the menu at left about Getting a local copy of your data.