What is the best way to add a Windows OS to an MBP and MBA? I have heard of bootcamp and a software called Parallels (?) but I am not familiar with either. Thanks!
If your Windows programs will be resource intensive then use Bootcamp. If you will be running run-of-the mill Windows programs like word processing then use a virtual machine like Parallels, Fusion, or VirtualBox to install Windows.
Using Bootcamp allows Windows to use all your computer's resources. Using a virtual machine is more convenient.