You will have a great time, there are loads of different bikes and child seats/trailers, after you have arrived go and hire them. Haven't used creche but many on here have, we have used the babysitters who are wonderful (as many other parents have agreed here). Restaurants are OK priced, look out for early-specials, they all have high chairs and childrens menus, and colouring, and play corners ..... it really is all very child friendly. We really didnt enjoy our Pancake House meal, big pile of stodge! Aqua Sana is bliss,if you can live without her, let her off for a 3 hr morning session, they do ladies only, and it is so relaxing, lots of steam rooms, saunas, chill areas. I have had a wrap treatment there, but although I felt pampered I didn't feel very pummelled, so would probably have an aromatherapy massage next time.
The great thing about CP is you can do as much or as little as you like, and you feel as though you have been away for ages!
Take a bath mat for your ds (for inside the bath). Take some shopping with you to fill the fridge so you avoid the supermarket at the beginning, and it will be slightly cheaper. If you have bicycle locks take them with you, you can hire them though.
There are lots of CP threads, some very recently, if you do a search.
Have fun!