As first time cruisers, we didn't know what to expect on our New Year's Eve cruise. We husband and I traveled with our three year old and stayed in a cheap inside cabin.
Embark/Disembark: Easy enough and what I'd expected. Yes, lines, but nothing daunting, even with a kid in tow. The staff in Jacksonville were particularly friendly.
Kid info: Our son was content to spend all day, every day playing in the water slides. There were three different types of slides with varying levels of thrill. Our three year old must have gone down the "kiddie slides" a thousand times over the course of the cruise. There was not a dedicated kiddie pool, so the slide/splash area had to suffice. (In fact, there is only one pool on the entire ship, and several hot tubs). One negative is that the deck was a bit slippery. I saw many kids fall, but none get hurt. Our son only visited Camp Carnival for a couple of hours on the last evening, but he says it was his favorite part of the cruise. Go figure!