We have a dedicated guest room with an attached bathroom. It's the only bedroom on the ground floor which should gives pretty good privacy.Â
Honestly, if you want to, you can just show up. There's a bed, you lie on it; there are nightstands, you put stuff on it; and there is a shower, which sprays water. That said, we put a few "fun" things in the guest suite and you might want to check these links out as references if you want to know more about them in advance.
Phillips Wake-Up Light
ChromeBox - Just in case you don't want to or don't have to bring a computer with you