Miscellaneous Setup 

From the Main Menu, select Setup | Miscellaneous:

"Main Window Title" lets you change the text that shows at the very top of the main window. This is especially useful if you use multiple databases. Then, you could easily see which database was the current one by looking at the main title.
"Show ID in title bar" lets you show the patient number or the chart number in the title bar
"Process Signal Interval" refreshes commonly used information, especially the appointment screen. Details available in Refreshing.
"Use Random Primary Keys" option turns on support for Multiple Servers. It is very important to understand how this affects your database before you decide to enable it.
"Web Service: Server Name" is used for the Web Service.  It identifies which computer is running the web service.  Leave it blank unless you are using the web service.

Task Lists
"Always show task list" The Task Lists will show at the bottom or right of the screen in all modules rather than requiring user to click a button from the Manage module.

Communications files:
In the Main Toolbar, there is a Letter button for a simple letter.  You can set up your own jpg background and specify it here. On the Main Toolbar Letter button, there is also a dropdown menu item for Stationery.  This lets you specify a Word document for a simple letter. There is no further documentation on the jpg background or on the stationery backgrounds.  You would need to be a fairly advanced user, and figure these out on your own.