Since the ship is so huge, I figured I'll do the ship overview by deck. Remember, always call them "Decks" and not "floors", and the rooms are "cabins" or "staterooms" LOL. And, she's a "Ship" not a "boat"!
Deck 2 is not shown in the handout, or the Royal Caribbean book. It houses the medical facility. This might also be the deck you go ashore from. On the Freedom class, there are cabins down here, but not on the Oasis class. We didn't enjoy being on deck 2--too much engine noise and docking noise.
Deck 3 has the lower level of the dining room at the stern end (not quite at the stern actually, due to the Aquatheater). Forward of that are some inside cabins, and ocean view cabins. Studio B, the ice rink, is mid-ship, though I don't think you can access it on this level. Forward of that is the conference center, which we did not check out. At the bow is the lowest level of the Opal Theater, where they have the stage shows. Again, you don't access it here, but that's just where it lines up.
Deck 4 is where the action starts to happen. There's the middle level of the dining room, with some private dining areas. We were on the left side, if you were looking towards the bow. It was a weird area, somewhat closed in, without a view of the middle, open area, but with outside views, which would be nice if we had the earlier dining time or were cruising in the summer. Couldn't see much at night. I wonder if we got this small table because our cabin had been originally assigned to a couple who were higher up on the "rewards" list.
We started with another couple at our table, but they lasted only one night, so we had a table for 4, to ourselves. A bit lonely, LOL, but we got great attention from the staff and could get in and out in record time. I didn't get any good shots of the dining room this time, but it's pretty much the same feel as the other cruises we were on, so you can check out those blog entries.
Mid-ship is the casino, with Studio B just forward of that. On the Freedom Class ships, you could not walk from one end of the ship to the other end on deck 3 (the deck with Studio B), so we had to continuously go back up to Deck 4, and through the Casino to the other end of the ship, so we could get back to our cabin on deck 2. Not a big problem--but the Casino is pretty much the only place inside where smoking is allowed. Icky. We were thrilled to find out that the wider Oasis ships allows for room around the ice rink, and we were able to avoid the Casino most of the time.
Forward of Studio B was "Entertainment Place" (which technically includes the ice rink and casino, I think). "Blaze", "Comedy Live" and "Jazz on 4" were down here. We saw a comedy show, and I was surprised at how small the comedy club felt. I don't recall checking out Blaze or Jazz on 4 (despite loving jazz!). There is also the "Hall of Odds" leading into Studio B--just a little wall display on the history of gaming. At the bow is the main entrance to the Opal Theater. I don't have pictures of these places since we really weren't down there much. I'm sure you can find pictures on Royal's website :)