Well out of sheer frustration, I once again started from scratch. While both the "Standard" and the "Workgroup" setups seem similar, I opted for the "Standard" setup to start.
I believe the one key element to success is to choose Open Directory as one of the first services to set up... there is a list you check during setup, and Open Directory is one of them.. I checked it, and iCal, and File and Print Sharing, and most likely e-mail as the only services for the server to set up and auto configure for me.
Once that was done, I added a user or two, and things became much clearer.
On 10.5 Clients, go to the Utilities folder, and look for an application called Directory Utility, and launch it.
It's possible that your server may have been found by the client, but if it is, I'd elect to delete it and start afresh just to be sure everything is correct.
For clients INSIDE the office, when asked for the server name or IP address, I entered the IP address of the server, and it went into auto pilot after that, asking me if I wanted it to configure the client computer.... in my case, I checked Yes.
It will then configure the client to use the services you've set up on the server(so, in reality, you may want to wait 'til you have more services up and running).
It asks for your username and password on the server, as well as the password for the client machine. As I understand it, if the client password is different, it will change the password on the server to match(but my password is the same, so can't promise what happens when they are different).
It DID configure both e-mail and iCal to work correctly with the server. In iCal there is a new listing on the left called yourdomain server, and one default calendar there. You can add more if you like.
Once you have several users up and running, in the client iCal prefs, under the Accounts tab, there is a tab for "Delegation". This is were you allow other users to see and /or write to your calendar. Click the "Edit" button, and the rest should be cake. The users must be valid users on the server. Likewise, there is a window showing accounts you can access and the privileges you have there.
In my case, I'm not so much working with others, but am looking for a replacement for the iCal sync function of Dot Mac. I was able to log into my account on the server from a computer at work, one at home, and a laptop. All three reflect changes made on any of the client computers I operate.
(As a note... for the laptop, which is sometimes IN the office and sometimes OUT of the office, as well as the computer at home, in Directory Utility, I used the FQDN of the server. This connects to the server from outside the LAN and works just the same as if I were inside.)
Now if only there was an option of what to publish in the server.... with Dot Mac, I elect to publish only that there is an event.. no name or anything else... this allows clients to see when I'm busy, but not who I'm busy with. Unless I can figure out how the calendar can be seen by anyone on the web, AND I can hide the event info, I'm stuck on Dot Mac.
I WISH I had an answer for the "no virtual host" issue. I did run into a problem with a web site, and found the only way to fix it was to delete the web site entry in the Server Admin, then re-instate it again, and all was well. I'm thinking it MAY be possible to delete the iCal service in Server Admin, save changes, re-start the server, then add the iCal service again.... its possible that will get you around the No Virtual Host message, but since I started over, I can't test to tell you if it will or wont work. I can tell you that there is nothing in the iCal Server Admin that is vitally different that what was there before, so I'm at a loss about the no virtual host message.
Soooo that's my iCal service story. Long, hard, bitter, and difficult. I've said this before, but Apple really need to create some type of "Re-Initialize" server button to put you back with a fresh install, instead of having to re-install it. I've lost track of how many times I've done that with 10.5, and know I had to do it with 10.2, 10.3 and 10.4 as well. For now, I'm on the Standard Setup, but intend to migrate to the Advanced after this seems stable AND I've got a good working copy on a separate drive to go back to should things go haywire. I can say that while I've have had to use Server Admin some(for the firewall for sure), there seems to be no interference between the settings I make in Server Prefs and Server Admin.
Jag har för skojs skull kämpat lite med både grupp-wikis, bloggar och kalender och det är tyvärr inte så pass enkelt att bara starta & köra (i alla fall inte iCal-server). Det blir mycket meckande, särskillt om man vill ha egna skins till bloggar/wiki. Kalendern är nog den mest struliga tjänsten (tycker jag) i hela OS X Leopard Server.