The best way I found is a simple 7-step process:
1. Purchase a copy of Acronis TrueImage and set-up a TrueImage bootup CD.
2. Prepare a 'template' PC. It needs to be set-up, configured (user, domain, etc), and all applications working.
3. Download as many drivers as you think you will need (especially if you are going to use Wireless, as WIFI cards are not easily recognized by XP) and put them on folders on the PC.
4. Run a Sysprep utility with the option that enables you to make XP detect the hardware turned on (look at sysprep documentation and options).
5. When the sysprep is finished, do NOT restart the PC from the hard disk. Reboot the PC from the Acronis CD and make an image of the PC partition or disk (it is extremely easy). Save this image to CD although I prefer network drive.
6. Finally, when you set up a new PC (or laptop), simply pop in the Acronis CD and install the backed-up image from CD or network drive. When the PC is rebooted, it will go through hardware detection and whatever option you defined in sysprep
7. When the new PC reboots, it will be completely ready - applications, settings, shares, etc.
Note: Step 1 is once for all. Step 2 to 4 take the longest but needs to be done only when you define new company PC specifications. Step 6 to 7 usually take about 20 minutes. Think about it, 20 minutes to set up a PC to your company's specs!