I have a late 2008 MacBook. I've never tried booting off another drive, but I may need to start soon. Is it possible to use that MacBook to boot off a USB drive (rubbing Windows)?
Sure... assuming the USB drive has a bootable image of OS X on there, just hold the option key when booting and select the USB drive as the boot drive.
Edit: You mean USB boot to Windows? Not gonna work.
If you are at least any bit competent with a screw driver, white MacBooks are insanely easy to upgrade. Simply remove the L shaped shield inside the battery bay and remove the hard drive. If it is an Aluminum MacBook, it is very easy as well. Simply remove the battery and the mounting bracket. Then just transfer the four mounting screws to the new drive.
This is a six year old Mac and it is worlds behind the new ones. I am offering the ability to upgrade it and let it serve you a few more years.