I don't think I am using anything but Apache and Rails.
How can I tell?
How do you start your app on this server? `rails s` or ... ?
One of the things that is confusing me is I have a file /etc/apache2/sites-available/ThisWorks.com.conf
How does Apache know which *.conf file to use?
The VirtualHost/ServerName/ServerAlias directives -- if you tried to access a different hostname on that same IP address it would just show the default host (from sites-available).
Is there a book you can point me at that goes through this stuff in much greater detail?
I have no idea about a book; there are probably lots of tutorials out there. The config files are super well-commented, though, and I'd just start there, along with the online docs.
Note: the Apache httpd is based on Rob McCool's original NCSA
server circa 1993 so it's pretty "battle-tested" and that includes the
documentation 