Installing on an alternate boot drive

[CheriMo]

I see a lot of instructions and advice on now to install Ubuntu if you have a computer running some flavor of Windows or one running Mac OS X. What if you don't have those? Are there instructions on how to create an alternate boot device with Ubuntu and not setting it up to simultaneously run on a machine running Windows or Mac OS X? I have an HP Mini 1000 with that HP MI proprietary interface. My husband loves it and doesn't want me get rid it. I want to play with plain, old vanilla Ubuntu that looks just like the documentation I have on Ubuntu, but I also don't want to make my husband mad. Therefore I want to create an alternate boot so when my husband turns on the machine, it'll remain as is for him. But when I want to play and learn I can boot the alternate device and goof around to my hearts content. I know there are some instructions out there, but the problem with them is that they assume that if you have a machine that's already running Linux of some flavor, you know what you're doing. I'm new to Linux so I feel like I'm falling through the cracks here.

CheriMo