I've started to notice more and more as I study the ISS, that I can only ever find pictures of **one** Soyuz docked. Where is the other one?

Lets say their sending up a crew of 6 for an expedition.  
A Soyuz craft can only carry 3 at a time ([**wiki**][1]), thus meaning another one has to launch later.<br>(Which is why theres always a period where only 3 of the 6 are on the station)

**What modules** do **both** the Soyuz dock to?  

I also feel that I might be looking at this the wrong way. Please correct me if I'm wrong that both are docked at the same time?

**Also, can someone please add correct tags, I have insufficient rep and can't find any relevant ones.**

  [1]: http://en.wikipedia.org/wiki/Soyuz_%28spacecraft%29
  [2]: https://i.sstatic.net/kQvh4.jpg