Not a home or media server
One thing I've been asked about the Mini server is whether it would work as an effective home server. While it can function as a household file, print, and backup server, you'd be better off with Apple's Time Capsule. It's designed to be a wireless access point, a network storage, and print server for both Macs and Windows, and a network-based Time Machine backup location.
I'm also asked whether it might work at home as a media server. And I give the same answer: It's possible, but it isn't the best option. Home media servers come in many forms. The simplest, from an Apple perspective, is to use the sharing features built into iTunes running on a Mac or PC in your home. You can even dedicate a low-end machine to media server duty and have an excellent -- and cheaper -- setup that other machines can access. Or you can use network-attached storage devices that are designed to act as a central repository for media that can be accessed by other computers, set-top boxes and other devices. Using a Mini server is almost certainly overkill, and while it can run iTunes and other media tools, so could a $499 Mac Mini, an iMac or a low-cost PC.
Setup and performance
Setting up a Mac Mini server is easy, even for someone who's never set up a server before. Snow Leopard Server comes preinstalled, and the Server Assistant utility is launched automatically on first start-up. The assistant automatically detects the network environment the server is connected to, asks easy-to-understand questions about the type of setup and services you want, and creates the primary administrator account in just a few minutes.
With the initial setup complete, the available services are pretty much ready to go. You can choose to have the server automatically configure new or existing workstations to access its resources and services, send invitation e-mails to existing users with computers that may already be configured, or set up access manually.
In its default configuration, the Mac Mini server includes two 500GB internal hard drives, with the second drive occupying the space normally reserved for a traditional Mini's optical drive. Like the MacBook Air, you can install software and even erase and reinstall the operating system by sharing an install CD/DVD from the drive of another Mac or Windows computer on the same network. You can also buy the $99 external USB DVD drive available for the MacBook Air to use with the Mini server.
There's no real right or wrong way to work with the configuration of the two internal hard drives. By default, they exist as two different, unpartitioned volumes (one of which is used as the server's start-up drive). You can keep this configuration and use both for storage or use one as a backup drive. You can also combine the two using RAID to act as either a single large volume, a striped volume for increased read/write performance, or a mirrored set in which data is written identically to both drives so that in the event of a failure of one drive, the server will continue functioning without interruption.
Each option is fine, depending on your needs or preferences. The one setup I wouldn't recommend is using the second internal drive for Time Machine backups. For convenience and a bit more security, I'd use a larger external drive that's at least 1TB.
The Mac Mini server comes with only a single Ethernet interface, but it also offers 802.11a/b/g/n wireless, making it an ideal choice in businesses and offices where cabling may be difficult or costly. If additional Ethernet interfaces are needed, you can use the USB-to-Ethernet adapter that Apple sells for the MacBook Air. The five available USB ports give you some room to expand Ethernet access.