First steps
The first step in getting my system infected, er, I mean installed with XP, as well as OS X, was a trip to Apple's Boot Camp Public Beta web site.
Boot Camp weighs in at 83MB, so it's a fairly quick download if you have broadband. Once I'd downloaded it, I needed to extract the package to my lovely Intel-based MacBook Pro – there's no support for G3, G4 or G5 processors in Boot Camp, it's an Intel-only app.
The app installed a couple of items onto my Mac, including a tool called Boot Camp that goes into the Applications folder under Utilities. Before running that tool, though, it's critical that you prepare your Mac.
Backup everything on your system – and I do mean everything. There's a risk that things could go wrong and destroy your data.
Update - April 14, 14:00 - Bob
Crabtree adds - Just to ram home the point about doing a backup, you
might care to read this Apple
forum thread. A
number of people there are saying that Windows XP is running okay but
they've lost access to their OS X partitions - and, in some cases, it
looks like they might end up having to zap those partitions and lose
their data and program set ups. What's unclear, though, is whether or
not the people who had problems properly followed Apple's installation
instructions.
I'd also recommend that you run Disk Utility to repair any permission problems and check your disk for errors.
The next two steps are also very important. First, download the Boot Camp Setup Guide and print it off. This is a 390KB/17-page page PDF document and you want to have it to hand as you go through the set up process.
Next, install the latest 10.4.6 update along with the latest firmware update relevant to your Intel-based Mac. All the firmware updates for the three Intel Mac models are available on Apple's download site, so I just had to pick the right one for my MacBook Pro.
The firmware upgrade comes with full instructions and took five minutes to install. All the upgrade does is add in support for Bios but this is the key to getting Windows working on your spangly new Intel-based Mac.