I want to transfer files from one Mac to another. How do I do that? [9 & X]
There are many ways to move files from one computer to another: you can email them to yourself, burn them on CD or DVD, or copy them via Zip disks or an external drive (USB, FireWire, or SCSI, depending on your computers). In some cases, you might want a backup program like Retrospect to make a precise backup to tape or other media. You can also put files on an Apple iDisk or other network servers and then copy them back to the other computer. If both Macs have FireWire, you can use FireWire disk mode (press T while the computer is starting up) to make one computer act like an external FireWire drive that you then connect to the other computer.
Finally, you can network the two computers and use File Sharing to move files back and forth. This may be the best approach if you will be moving large files back and forth regularly. There are three steps: network the computers with wires or AirPort, share the files on one computer, and access the files from the other computer.
How do I physically network two or more computers? [9 & X]
If you are using AirPort or a DSL or cable modem router, the computers are already networked.
If there are two computers and nothing else, plug an Ethernet cable between the two. All current Macs autosense what they are connected to, so you don't need a special crossover cable (but a crossover cable works between any two Macs, even ones that don't autosense). ...