CCNA really gives you a basic understanding of Cisco technology. It also proves you can study a technical subject. You might want to work for a networking company or a general company. Within a networking company you might do just Cisco or Cisco and others. When applying for jobs remember once you are on the inside you can always move so do not worry about the initial work there is nothing wrong with getting your hands dirty.
I would suggest getting a little home lab setup with a few routers and switches. It will help in your learning process tremendously.
As far as what doors the CCNA will open - should help you quite a bit vs. not having any Cisco certs. But what also makes a big difference is your experience. A combination of certs + experience goes a long way.