As your company grows and you add employees, computers, and an office to house them, you'll need a network to connect everyone to each other and to the Internet. But at this point maybe your startup crew uses a collection of Macs and PCs, with the graphics people favoring OS X, the software developers relying on the tools that come with Linux, and everybody else preferring Windows. Fortunately, these three operating systems can communicate and coexist on a single network. By using suitable off-the-shelf networking equipment and the various operating systems' built-in tools, you can connect your heterogeneous hardware to the universe in short order.

First, There Was Ethernet
Your first question when setting up an office network may be "Wired or wireless?" Unless you have serious security constraints, the answer should be "Both." Wireless networks are more convenient, allowing untethered laptop users to work anywhere in the office. Wired connections are the better choice for stationary PCs and printers because they're faster, more secure, and easier to configure--and they leave maximum wireless bandwidth for your free-range connections to use.

Before you run out and buy the first $99 wireless router you see, however, take a moment to assess your specific networking needs and your office's topology. First, is network wiring already in place? If so, does it go to the places where you want to connect computers and other networked devices, such as printers?

Ethernet cables are fairly inexpensive. To create an uncluttered, professional-looking environment, however, you may want to have an electrician install ethernet cabling in the walls before you move into a new office space. But even if your budget is too tight for electricians and interior designers, it makes sense to draw a plan showing where your connected and wireless devices will be.

All of that wiring has to end up somewhere--and often the destination turns out to be a closet, where the cables plug into an ethernet router. The router does a number of important jobs: providing computers on your network with a private, local IP address (required to communicate with each other); coordinating connections between those private addresses and servers on the Internet; and blocking unwanted incoming and outgoing connections with a firewall. The router may also incorporate a wireless access point.

If your Internet connection enters the premises in the same closet, so much the better. And if your business is small--say, five people or so--you may be able to get by with a cheap wireless router after all (for likely candidates, see our most recent roundup of wireless routers). Most routers incorporate a wired ethernet hub with three to five connections, and a few offer eight ports--the more the better, for a growing business.

If you need additional wired connections, you'll have to purchase an additional ethernet switch that you can set up between the router and the clients to increase the number of available ports. Most routers can assign addresses to up to 254 devices (wireless and wired), though some of them top out at 20 or so wireless clients.

Still, even the fastest wireless routers may show signs of bogging down when hosting ten or more active users, depending on the bandwidth demands of each. Alternatively, you can opt for a wired router (with lots of ports, of course) and a separate wireless access point that connects to it. Walls, masonry, metal cabinets, and other structures can interfere with the radio signal used by wireless ethernet, so a wired router plus wireless access point is a good option if your network wiring hub is fairly distant from your wireless workers.

For optimum performance, position your wireless router or access point as close as possible to the wireless work areas. Upgrading to the latest wireless technology--the draft 802.11n specification--can significantly speed up your wireless connections as well. Sometimes draft or nonstandard wireless technology delivers its best results when you purchase the router or access point and the wireless client hardware from the same manufacturer. Read the manual before installing a router, and be sure to heed its urgent warning to change the router's default password before connecting it to the Internet.

Hooking Up Printers
One great reason to network your business PCs is to share printers. Printers that connect directly to the network via ethernet constitute one of the most brilliant innovations ever. Simply plug a printer in and turn it on, and soon it is available to every computer on the network.

To find and install a network printer in Windows, go to Control Panel, open Printers and Faxes (just plain Printers in Vista), click Add a printer, and use the network printer option in the resulting dialog box to browse for the printer on the network. Windows Vista will detect and install a driver for it, if one is available online; Windows XP offers a list of available drivers. Network printers may not show up in Windows XP if your Workgroup name differs from the one that the printer belongs to (often, 'WORKGROUP'). To locate the printer, temporarily join its workgroup (click Change in the Computer Name tab of Control Panel's System Properties) before browsing for the printer. In general, it is much easier to share resources between computers if all of them are configured with the same Workgroup name.

To find and install a printer in OS X 10.5, open System Preferences, choose Print and Fax, click the lock icon to allow changes, then click the plus sign to add a printer. If your printer doesn't appear in the Default list of printers, you may find it listed under the Windows category, which allows you to select printers shared on any local Windows Workgroup. Select the printer and click Add. To install a printer in Ubuntu Linux (the popular distribution we use as an example in this article), choose System.Administration.Printing, click New Printer, select the printer in the resulting list, and click Forward to select the correct driver and install the printer.

The wonderfulness of networked printers notwithstanding, you may want to share a printer that's connected directly to a PC with other computers on the network. To share a printer in Windows, first enable file and printer sharing. In Windows XP, open Network Connections in Control Panel, right-click your active network connection and choose Properties, check File and Printer Sharing for Microsoft Networks in the 'This connection uses...' list, and click OK. In Windows Vista, open the Network and Sharing Center in Control Panel, expand the Printer sharing section, select Turn on printer sharing, and click Apply. While you're there, enable Network discovery and File sharing if you want to share your files with other users on the network. Next, in the Printers and Faxes dialog box, right-click the printer you want to share, select Share this printer, enter a name in the 'Share name' field, and click OK.

In OS X, select the printer from the list of printers in Systems Preferences' Print and Fax page, and check Share this printer. Although Ubuntu can share its printers with other systems--and browse Windows printers by default--it can't share its own printers as Windows shares until you install the Samba utility, which emulates Windows' Server Message Block (SMB) file-sharing and printer-sharing protocol.

The fastest way to install and configure Samba in Ubuntu is via command-line tools. Nonexperts can install the program graphically, however: Choose System.Administration.Synaptic Package Manager to open Ubuntu's software installation interface; then click Search, enter Samba, and click Search.Scroll through the resulting list, select the entry that reads simply Samba, and check it. Synaptic package manager will select the other necessary packages. To install the software, click Apply. For details on configuring Samba, start with the official guide.

Share Your Files
Like printers, storage can be much more useful when it's networked. In the past, sharing files meant dedicating an entire computer to the job. Now, Network Attached Storage (NAS) devices--often no larger than an external hard drive--provide always-available disk space to anyone on the network via the lingua franca of file sharing, the SMB protocol.

To connect to an SMB share from Windows--whether on a NAS device or on another computer sharing it via SMB--open My Network Places, and browse the shares available on the current workgroup. As with printers, Windows XP will show only the shares available on the workgroup you are a member of. To view files shared on the local network via SMB in OS X, browse them in the Finder; available servers are listed under 'Shared' in the window's left-hand pane, or choose Go.Network in the menu. In Ubuntu, choose Places.Network.

As with printer sharing, not all storage is attached directly to the network. OS X, Windows (Vista and XP), and Linux all allow you to share files stored on your computer with other users on the network, as well as to browse file shares on other PCs. To share files in Windows, first enable file and printer sharing (as detailed above). In Windows XP, browse to the folder you want to share, right-click it, choose Sharing and Security, and check Share this folder on the network. If you want other users to be able to edit, delete, and create new files in the shared folder, check Allow network users to change my files. Click on OK to finish.

By default, Windows Vista requires users to provide a log-in name and a password before they can gain access to its file shares. If you'd like to share files with anyone on the network without having to create a user account and a password for each person, set Password protected sharing to Off in the Network and Sharing Center before you attempt to share files or folders. To share a file or folder in Windows Vista, right-click it, choose Share, select Everyone (all users in this list) from the list of users and groups available to share with, click Add, and then click OK.

To share files in OS X, open System Preferences, click Sharing, check File Sharing, click Options, select the shared home folders (if any) that you want to share via SMB (public folders are shared by default), check Share files and folders using SMB, enter the account password for any checked home folder when prompted, and click Done. To share a folder with everyone on the network in Ubuntu, select the folder in File Browser, choose File.Properties, select the Share tab, check Share this folder and Guest access, andclick Create Share.

After following all of these steps, you should have your company's network up and running. Now your employees can focus on advancing your business to the next level.

Scott Spanbauer is a Contributing Editor for PC World.

This story originally appeared on PCWorld