After loading tomcat6 and apache2 packages (and dependencies) via synaptic, we deployed subsonic.war to tomcat (just toss the war into the deploy directory) and fired up tomcat (we start/stop using Boot Up Manager because its GUI, but you can do the same thing at command line). Then we setup a redirect page in apache by editing the /var/www/index.html page:
<html>
<head>
<meta http-equiv="refresh" content="0;url=http://server:8180/subsonic/">
</head>
<body>redirecting...</body>
</html>
Other than that, it is pretty much the default tomcat and apache configs.
We also loaded the default startup script to init.d for tomcat6 so that it is auto-started on boot. So we just hit
http://server, which then shows the redirect and then we are at the subsonic login.
You could get a lot fancier with this, but this is fairly clean and simple. Our httpd.conf file is blank since we are always doing the redirect, but you could use apache to do the redirect a little more permanently without the browser redirect. (we are basically having the browser refresh to the new address)
There might be some config that I forgot about doing, but I think that was the important stuff... We downloaded the transcoding libraries we needed (faad, ffmpgeg, flac, lame, etc) and put symlinks into the /var/subsonic/transcode directory to get transcoding working, but those are unrelated to the web setup...
As a note, you could just run tomcat and connect directly to the address, but we liked not having to remember the port (and apache is very stable so we never have to mess with it).
BTW, subsonic upgrades are super simple: 1) Stop tomcat, 2)Drop the new war (delete the temp files created from the last deploy - see war deploy instructions) 3) Start tomcat. The DB and properties are all in /var/subsonic, so you don't have to reconfigure anything.