Me and my younger sister took our first cruise on Carnival Liberty the first week of March - sailing the Eastern Caribbean itinerary. This was our first cruise, though I've traveled pretty extensively in the Caribbean previously, so I wasn't sure what to expect. In all, we had a wonderful vacation and I was pleased with the cruise experience.
Embarkation: We made the mistake of waiting until after noon to get to the dock and, even though we had completed the "Fun Pass" on the internet beforehand, it probably took us almost 2 hours to get through the check-in and immigration process. I would recommend heading to the port around 11 am to avoid the long "Disney world" type lines. Once on the ship, we checked out our interior cabin, changed into our swimsuits, grabbed pina coladas and staked out some deck chairs on Lido Deck 9 to enjoy the Florida sunshine.
Cabin: We had an interior cabin in the middle of the ship on Deck 8 - one deck below a lot of the activities on Deck 9. It was a great location. The room was small, but the beds were super comfy and the bathroom was totally manageable. There was only 1 U.S. outlet, so be prepared for that. If you have a converter, you could use the other European style outlet, but I left mine at home and so we were limited to the use of 1 outlet throughout the week. Definitely bring an alarm clock, as the interior rooms are VERY dark and somewhat disorienting in the morning. It's really hard to get out of bed when it's so dark!! We were happy with all the storage space - and it was plenty of room for the 2 of us girls and all our outfits and shoes. We also brought portable speakers for our Ipod and so could listen to music in the room while getting ready. Our cabin steward was super friendly and knew our names by the 2nd day, which really impressed us.