We have been on two Carnival cruises and will go on our 3rd in April. We (me, DH and 12 year old DD) love to cruise and Carnival is a great deal. Your food is taken care of and there is some type of food available 24 hrs a day. There are lots of activities and in the evenings there are shows each night ranging from magicians to comedians to "Vegas-style" shows. As the commercials say, you really can do as much or as little as you want.
If you have any specific questions you can PM or e-mail me.
A couple of cruise mesage boards I like to visit are
It's a smaller message board, but many of the posters are experienced cruisers and are friendly and always willing to answer cruise questions.
This board is a bigger board with more members, but it is also a very friendly board.
What I like about both of these boards is the fact that the administrators allow "off topic" discussions. Some other boards I have visited won't tolerate any off-topic threads and some can be a tad clique-ish.
Wherever you choose to go, I hope you have a great time!