You don’t need a Time Capsule to do backups. If you want to use Time Machine, which automatically backs up your drive every hour or so over wireless and allows you to “go back in time” to restore your system to a configuration in the past (and which requires 10.5), then you do need a Time Capsule. (Time Capsules also double as wireless routers).
But if you want to do backups and you don’t mind plugging in an external drive every few days or once a week, than it’s easy to do backups on inexpensive, external USB drives and with free software. But you have to remember to do the backups; they won’t happen automatically as they would with a Time Machine. You can use Time Machine with an external USB drive instead of a Time Capsule, but some people don’t like the constant disk activity that takes place and want to do backups on their own schedule.
First, check the size of your hard drive before you buy a USB drive to make sure you get one that has enough capacity. Highlight the hard drive icon on your desktop and then select “Get Info” under the File menu, or hold down the Apple key and hit the “I” key. Look in the information window and find “Capacity.” That’s the overall capacity of your hard drive. (You might have to tick the right pointing arrow next to the word “General” to reveal capacity and free space.)
Then, get a USB drive with at least the capacity of your hard drive. The hard drive you get might have a cable with a double “tail” on it. The smaller USB end goes to the hard drive, but the larger end, which might have two connectors, goes to your Mac. Use the end that has the pair of cables attached to it; the other is for dual power, if needed, on an older Mac with USB 1.0, so that the drive can get power from two USB ports instead of just one.
Now, for the backup utility. I’ve used several different hard drive backup utilities, and I like Carbon Copy Cloner the best. It’s a free download here.
It’s a great program that will make a “clone” – or a bootable copy – of your hard drive on an external USB drive. So you get two things: you get a full backup of all your files, and if your hard drive crashes, you can put a new hard drive in your Mac and copy everything right back onto it and it will work as if nothing happened. And you can also work off the hard drive while you wait for your Mac to be fixed.
CCC copies all of your files, but also all of the file system metadata, the important “invisible” data that you never think about until it’s gone and you’re trying to do a full restore of your hard drive’s data to a new drive.
The first time you run CCC, a full clone might take a up to few hours or more, depending on the capacity of your hard drive. But after that, CCC will synch your drive and only copy over the files that have changed, so the subsequent backups will be faster. My backups take half an hour or so. I start it up last thing at night and just let it run by itself.
You can start up CCC and check out how it is going to run without doing a backup. Look in the “Help” menu and read the instructions for which kind of backup you want to do. And look at the CCC web page, too, and read the online forums if you have questions.
You can do scheduled backups with CCC, too, something like a Time Capsule. But the simplest is plugging in your external drive and starting up CCC and selecting your USB disk and the source disk, which is the internal hard drive of your Mac, and letting it run.
Just remember to run a backup as often as you feel necessary, because the safety of your files is only as good as the last backup you made.