RCI are great for most age ranges - there are about 6 kids clubs for the various ages and they are kept pretty active I hear. All ships have rock climbing walls and mini golf - the big Freedom Class and Voyager Class also have ice rinks!.
At night there are the usual 'shows' - dancers and comics and magicians etc - and there is an iceskating show on the ice rink.
The ships are visually very pretty - art work everywhere, There is one main dining room - usually 2 or 3 stories high, then there may be a speciality restaurant that will charge $20ph supplement but the food is worth it!
Suggest you go here - www.cruisecritic.com and click on the word 'boards' and then click on the link for RCI to read comments - usually "what do I wear on formal night" type questions - also when you have picked a ship and itinerary I suggest that you click on 'Read Member Reviews' link from the front page of cruisecritic [not very clear - half way down on the right hand side] and you can see what people say about your specific ship.
Cruising has a myth that it is for 'old' people, it is stuffy, you have to dress up in black tie every night etc - but it is certainly no longer like this. Yes there will be a formal night but if you don't want to dress up you don't have to - you won't be thrown overboard! Suggest you go to the buffet to eat that evening!
Make sure you pay the gratuities before hand - roughly �35pp for a week - if you don't it will be added to your account on board.
On board you can eat/drink 24 hrs a day!! So you can certainly get your money's worth!
Also use the 'Ports of call' section on the Boards to see what people suggest doing at your various ports of call.
I have 2 cruises booked for this year and am planning 3 for next year......can you tell?!?!