Hmm, with that VirtualBox, can I install Leopard as long as I have a CD or CD Image for it in a Windows Vista 64bit environment?
I wouldn't be sure.
I've managed to get OSX86 on my laptop before, and I've run it under VMware, but I don't think VirtualBox has the necessary support for it iirc.
Also in VMware it was atrociously slow. Without hardware acceleration the GUI is almost unusable (think XP without graphics drivers, but slower

).
As to the install itself, it's largely trial and error. You WILL need patched versions of the OS X CDs (can be torrented, obviously you should own a copy yourself though) and be ready for several hours of frustration as you poke the installer with multiple configurations and kernels followed by another few hours of poking drivers only to have the entire install die completely and need reinstalling.
It's NOT much fun I assure you. I finally broke mine running the OS X auto-update and I never got sound working under either VMware or natively.
What Virtualbox IS good for is running a Linux VM in Windows or running an XP VM in Linux. The last is very useful if you're not bothered about game support (VirtualBox lacks 3D acceleration) as you can dedicate a desktop to Windows and use the rest for Linux.
VirtualBox also has an integrated mode that will let you run Windows and Linux windows alongside each other. It's a very neat solution for many things but I doubt running OSX86 is one.