wilsonglasser: try to read again Ashley's posts just above yours.
The first (only) thing to do for you is to get a game on Steam.
Integration of steam API should not a big deal but it is only accessible to accepted games anyway.
If your game gets accepted, than you should think about this integration (and should get help for it anyway either by Valve and/or Scirra).
As for the workshop features, I'm not sure it's that relevant. (plugins are stored in the forum what could steamwork add to this ?)
Also what about ppl who only use the standalone version ?
Djfuzion: for now the steam version of C2 is only the stable (so r114). Ashley is working on having the beta version also working.
But as you said, it's off-topic of this thread.
I guess what you really need for now is this tutorial.