My kids are looking at Chromebooks, and none of us know anything about Chrome OS.... but there school is very "google-centric". They do almost everything with or through google.
Will it seem familiar to them? Can you run MS office? ( though they use google docs in school )
Chrome OS is for the most part Linux with a lot of focus around the web browser. In fact the entire UI is the web browser. It's pretty awful actually. No you can't use MS Office. The reason you buy a ChromeBook is to put Ubuntu on it, cause you can do a lot more with Ubuntu than you could with Chrome OS. Plus LibreOffice or OpenOffice is on there and it's free. I'm also pretty sure you can run MS Office on Ubuntu through Wine, though why?