LOL!!!! What no mention of Varangians or Finns? Since you're not lucky enough to be Slav and Eastern Slavic history is not your forte, all I can do is recommend a library or go to a good website with a timeline. The term Rus was well used before the introduction of Christianity.
The term "Rus" entered into history (entering into history means when a thing is written down) when the Greeks first recorded the name 'Rus' for a Scandinavian ruled Slavic people around Kiev. It is from that workd we get Russian. I need not be Slav to know this history.