1. Open any Finder window.

In the Shared category of the Sidebar at the left side of the window, icons for all the computers on the network appear. See Figure 15-8.

If you don’t see a certain Mac’s icon here, it might be turned off, it might not be on the network, or it might have File Sharing turned off.

If you don’t see any computers at all in the Sidebar, then your computer might not be on the network. Or maybe you’ve turned off the checkboxes for Connected Servers and Bonjour Computers in Finder→Preferences→Sidebar.

If there are a lot of computer icons in the Sidebar, or if you’re on a corporate-style network that has the sub-chunks known as workgroups, you may also see an icon called All. Click it to see the full list of network entities that your Mac can see: not just individual Mac, Windows, and Unix machines, but also any “network neighborhoods” (limbs of your network tree). For example, you may see the names of network zones (clusters of machines, as found in big companies and universities).

Or, if you’re trying to tap into a Windows machine, open the icon representing the workgroup (computer cluster) that contains the machine you want. In small office networks, it’s usually called MSHOME or WORKGROUP. In big corporations, these workgroups can be called almost anything—as long as it’s no more than 15 letters long with no punctuation. (Thanks, Microsoft.)

If you do see icons for workgroups or other network “zones,” double-click until you’re seeing the icons for individual computers.

Figure 15-8. Macs appear in the Sidebar with whatever names they’ve been given in System Preferences→Sharing. Their tiny icons usually resemble the computers themselves. Other computers (like Windows PCs) look like generic PCs.

2. Click the computer whose files you want to open.

In the main window, you now see the Public Folder icons for each account holder on that computer: Mom, Dad, Sissy, whatever, as shown in Figure 15-8. (They may have shared other folders with you, too.) If you have an account on the other computer, you’ll see a folder representing your stuff, too. At this point, you’re considered a guest.

From here, the remaining instructions diverge, depending on whether you want to access other people’s stuff or your stuff. That’s why there are two alternative versions of step 3 here:

3a. If you want to access the stuff that somebody else has left for you, double-click that person’s Public folder.

Instantly, that folder’s contents appear in the Finder window.

In this situation, you’re only a guest. You don’t have to bother with a password. On the other hand, the only thing you can generally see inside the other person’s account folder is his Public folder.

One thing you’ll find inside the Public folder is the Drop Box folder. This folder exists so that you can give files and folders to the other person. You can drop any of your own icons onto the Drop Box folder—but you can’t open the Drop Box folder to see what other people have put there. It’s one-way, like a mail slot in somebody’s front door.

If you see anything else at all in the Public folder you’ve opened, then it’s stuff the account holder has copied there for the enjoyment of you and your networkmates. You’re not allowed to delete anything from the other person’s Public folder or make changes to anything in it.

You can, however, open those icons, read them, or even copy them to your Mac—and then edit your copies.

3b. To access your own Home folder on the other Mac, click the Connect As button (Figure 15-9). Sign in as usual.

When the “Connect to the file server” box appears, you’re supposed to specify your account name and password (from the Mac you’re tapping into). This is the same name and password you’d use to log in if you were actually sitting at that machine.

Figure 15-9. You can sign into your account on another Mac on the network (even while somebody else is using that Mac in person). Click Connect As and then enter your name and password. Turn on “Remember this password in my keychain” to speed up the process for next time. The Change Password button lets you change your account password on the other machine. No matter which method you use to connect to a shared folder or disk, its icon shows up in the Sidebar.

Type your account name (long or short version) and password. And if you didn’t set up a password for your account, leave the password box empty.

Everyday Macs on your network. If you know the IP address of the Mac you’re trying to access (you geek!), you can type nothing but its IP address into the box and then hit Connect. Or you can just type its Bonjour name, something like this: afp://upstairs-PowerMac.local/.

Figure 15-10. The Sidebar method of connecting to shared disks and folders is quick and easy, but it doesn’t let you connect to certain kinds of disks. The Connect to Server method entails plodding through several dialog boxes, but it can find just about every kind of networked disk.

After you enter your account password and choose the shared disk or folder you want, you’re connected exactly as though you had clicked Connect As (Figure 15-9).

The next time you open the Connect to Server dialog box, OS X remembers that address, as a courtesy to you, and shows it pre-entered in the Address field.

Macs across the Internet. If your Mac has a permanent (static) IP address, then the computer itself can be a server, to which you can connect from anywhere in the world via the Internet.

Windows machines. Find out the PC’s IP address or computer name, and then use this format for the address: smb://192.168.1.34 or smb://Cheapo-Dell.

After a moment, you’re asked to enter your Windows account name and password, and then to choose the name of the shared folder you want. When you click OK, the shared folder’s contents appear in the window, ready to use, and the computer’s icon appears in your Sidebar. (More on sharing with Windows PCs later in this chapter.)

NFS servers. If you’re on a network with Unix machines, you can tap into one of their shared directories using this address format: nfs://Machine-Name/pathname, where Machine-Name is the computer’s name or IP address, and pathname is the folder path to the shared item you want.

FTP servers. OS X makes it simple to bring FTP servers onto your screen, too. (These are the drives, out there on the Internet, that store the files used by Web sites.)

In the Connect to Server dialog box, type the FTP address of the server you want, like this: ftp://www.apple.com. If the site’s administrators have permitted anonymous access—the equivalent of a Guest account—that’s all there is to it. A Finder window pops open, revealing the FTP site’s contents.

If you need a password for the FTP site, however, you’re now asked for your name and password.

Once you type it and press Return, the FTP server’s icon appears in the Sidebar. Its contents appear, too, ready to open or copy.

WebDAV server. This special Web-based shared disk requires a special address format, something like this: http://Computer-Name/pathname.

In each case, once you click OK, you may be asked for your name and password.

Once you’ve typed a disk’s address, you can click to add it to the list of server favorites. The next time you want to connect, you can just double-click its name.

The clock-icon pop-up menu lists Recent Servers—computers you’ve accessed recently over the network. If you choose one of them from this pop-up menu, you can skip having to type in an address.