Well, obviously we are seeing light that has reached us, otherwise we wouldn't be able to see it. But it has taken N billion years to reach us, so it represents the state of those galaxies N billion years ago, from our perspective. Likewise, we see the sun as it was 8 1/2 minutes ago because it takes light that long to get here.
Maybe you want to try the Cosmology FAQ? This is one of those sites I promise myself I will read one day...