HI thebog and welcome to the forums,
You can dual boot with relative ease, providing that you have enough room to make a second partition or a second HDD to install on, personally I have a second HDD for my Windows 7 install and have Vista on the other. Once you have installed you may have to repair your boot screen to include XP and change it back to the default OS, this can be done using EasyBCD with ease and if you have any problems there are plenty of people on this forum that will help you out.
Another thing you will notice once you have installed Windows 7 and booted it for the first time, when you look in Computer your XP partition will not be visible but don't panic it's still there, all you have to do is go to disk management and assign a drive letter and you will now be able to access your documents through Windows 7, also note you will need to aply any changes in EasyBCD after assigning your drive letter to your XP partition.
If you have a look around the forum you will find lots of XP dual boot threads started with answers to allot of questions, good luck.