You probably want to be able to get stuff on and off of A2SERVER, so that means connecting to it from other computers.
You can browse your network and you should see either "raspberrypi" or "a2server" as a server you can connect to. You can log in as Guest if asked.
On Mac OS X, it should appear under Shared in the sidebar of a Finder window, or under "Network" from the "Go" menu of the Finder.
On Windows, it should appear under Network.
On Mac OS 7 through 9, open Chooser from the Apple menu and click on AppleShare.
(If you can't browse to the server on your network, you may need to log in to A2SERVER to update, and if that doesn't work, to find its IP address. On Mac OS X, enter the IP address under "Connect To Server..." from the Go menu of the Finder; on Windows, type the IP address following \\ in an Explorer window.)
You will see two or three shared volumes: A2FILES, GSFILES, and, if you have A2CLOUD installed, ADTDISKS. Avoid the A2FILES volume except for copying things off of it. If you do want to put stuff on it, be careful to only use ProDOS-compliant filenames (all caps, 15 characters max, starts with a letter, and only contains letters/numbers/periods). Otherwise, you'll get unexpected behavior like invisible files.
Unix-type computers can also use
scp to copy files to and from A2SERVER; Windows computers can also do so in the command window by using
pscp in PuTTY. The shared volumes are within /media/A2SHARED.
If you need to set the ProDOS file type of a file you have copied to A2SERVER, log in to A2SERVER and use
A2SERVER home page