This hint is pretty obvious. I'm very glad, with OS 10.4 Server, Apple has implemented some form of managed preferences on a per-file basis. Yet in 10.4, they never added a UI for managing the Sidebar items in Workgroup Manager. Thankfully, you can just manage the file com.apple.sidebarlists.plist instead. I was a bit skeptical about this working at first, as I thought the home folder items (home, Documents, Desktop, ect) would break and you would get the "Original item not found" error. To my relief, they don't break.
There are two kinds of shared folders I want to add to the sidebar for my users. One (this is a hint'in'a'hint) is /Local Documents/ and this is a local 'everyone read/write' folder were users can save if they go off the network, server goes down, or saving to the server directly doesn't work (which is often an issue, especially with Photoshop on OS 9 or Office on OS X). The other, and much more beneficial, item(s) I will add (when I have time) are shared documents folders on the servers. Apple lets you add things like this to the Dock, but that doesn't help when you are in an open/save sheet.
You will want to log in as a user who is going to get the managed preference, and manually configure the Sidebar. Then log into an Admin account and connect to that user's home folder (who has the configured Sidebar), open Workgroup Manager, and add this file...
YourNetworkUser/Library/Preferences/com.apple.sidebarlists.plist
...to the managed preferences list for your User/Group/ComputerList. Putting these preferences under "Always" probably won't prevent the item from being "poofed," but I need to test that.
If there are any issues with the home folder items, I will just remove them from the managed preference, and let the OS create it by default when they login, and leave the other items I added. Also, if anyone knows how you can manage a non-plist file, or a file that is in a folder within the Preferences folder, please let me know!
Mac OS X Hints
http://hints.macworld.com/article.php?story=20051115191436237