Once upon a time Mac files and PC files were not very easily exchanged and if you wanted to run a Windows application you pretty much needed to own a PC. But happily those days are long gone and now many file types can be easily exchanged between the two platforms and a modern Mac can run current versions of Windows and most Windows programs using a free utility provided by Apple called Boot Camp.
You will need a legitmaite copy of a Windows installation CD to use Boot Camp on your Mac and it needs to be a pretty current version of Windows (Windows XP Home Edition or Professional with Service Pack 2 or later, or Windows Vista Home Basic, Home Premium, Business, or Ultimate). You will also need an Intel-based Mac computer running Mac OS 10.5 (Leopard), with at least 10 GB of free disk space and 2 GB of RAM.
The basic idea is that you will use Boot Camp to create a new partition on your Mac's hard drive that you will install Windows on. You will have to reboot your computer to switch between Windows and Mac OS X. (If this is a problem for you there are also some good commercial applications that allow you to run Windows and Mac OS X concurrently, check out Parallels and VMWare).
Apple provides a 26-page Boot Camp Installation and Set-up Guide, and it's well worth printing this document out beforehand and following it closely. Remember to make sure and do a complete backup before installing Boot Camp, as with any process that is changing partitions on your hard drive there is always the chance of something going wrong and losing the data on the drive. I haven't heard of anyone having serious problems installing Boot Camp, but "better safe than sorry" is a good mantra when it comes to messing with hard drive partitions.
There are three basic steps required to get Windows up and running on your Mac with Boot Camp. First, you need to run the Boot Camp Assistant program that comes with a default Mac OS X 10.5 installation. The Boot Camp Assistant creates the partition on your hard drive for Windows and gets you started with the actual installation of Windows on the new partition. Then you need to complete the Windows installation, and finally install the Boot Camp Windows drivers on your new Windows partition.
To run the Boot Camp Assistant you should log in to your Mac's administrator account and close any running programs. Then find and open the Boot Camp Assistant, which should be located in your Utilities folders (which resides inside of your Applications folder). Now just follow the on-screen prompts to create the new partition and assign the appropriate amount of disk space to the partition. This will vary based on your specific Windows-related needs, but select at least 10 GB.
After creating the partition, it's time to install Windows. First, choose "Start the Windows Installer" from the Boot Camp Assistant and then click on "Continue". Now insert your Windows installation disk and select "Start Installation". At this point control will be turned over to the Windows installer and you will be asked which partition to use for the installation. This is a crucial step, make sure and select the partition that includes "BOOTCAMP" in the title or else you may overwrite your existing Mac programs and files.
Now you need to reformat your Windows partition using the Windows installer. If you're installing Windows XP you'll get to choose between formatting the partition as FAT32 or NTFS. NTFS is more secure and reliable and can support partitions larger than 32 GB, FAT32 allows better compatibility with your Mac (you can read, and write to files in a FAT32 Windows partition directly from Mac OS X, but this is not possible if you use NTFS) but has a 32 GB size limit. If you're installing Windows Vista you don't get this choice as Vista requires a NTFS filesystem. Once you select your format option and follow the prompts, your computer will restart into Windows. At this point follow the Windows prompts to configure your copy of Windows.
The final step is to install the Boot Camp for Windows drivers, which are located on your Mac OS X installation disk. These Mac-specific Windows drivers allow your Windows applications to use the assorted peripherals that are connected to your Mac. From Windows eject the Windows installation disk by going to My Computer and selecting the D: drive and "Eject this disk". Now insert your Mac OS X install disk and follow the prompts to install the appropriate drivers. You will then need to restart your Mac and then follow the instructions in the "Found New Hardware Wizard" to complete the update of your software drivers.
That's all there is to it, you can now install and run Windows applications when you boot up into the Windows partition. You select which partition your computer will boot up into in the Startup Disk System Preference dialog box. You can also select which OS to boot up into on the fly during startup by holding down the Option key and then selecting your partition. Thanks to Boot Camp you no longer have to own a PC to run Windows applications.
Refer to Apple's Boot Camp Installation and Set-Up Guide for more details on how to use Windows apps on your Mac, like keyboard mapping, using the Apple remote control with Windows, and other customizations.