You'll have to change the fine parts of it as well; you can't just change the names and be done with it. Like Shadoe said, if you change a horse to a conij, you'll have to make it not a regular horse or you'll be better off calling it a horse (unless a conij is the name for a horse in your world).
Yeah, basically said everything above; you should try and research the furnishings of medieval time periods, if you're going for something like that. Otherwise you can even create your own. I don't really brood much on that; mostly just throw things in like beds and rooms, obviously, but I don't...
Most of my races are just amalgamations of other common fantasy races. You have the typical were-dragons, then it gets more complicated and you have to really see what the "faerolls" are. In my world there are thousands of different races, but that's just me cuz I've made a huge fantasy universe.
In my fantasy story, there's a place called the "Godlands", with seven gods (subject to change, though, since the names are rather hard to come up with :P). They are the ones who created my entire fantasy world, and as time went by, people became more and more aware of their presence. Of course...