sea world, the zoo, Balboa park, the Rueben H Fleet Science center would be great for them. you could take a tour of the USS midway as well. walking around coronado is always fun. so is checking out the hotel del. since you'll be in Carlsbad Lego Land might be good the the 8 year old. Pizza Port (very family friendly) and Stone (maybe keep that for just you and the missus) are musts. you're pretty close to both of them in Carlsbad. Ballast point (the home brew mart) is really cool and they have a great beer sampling bar. Green Flash would be another brewery to check out. you can't go wrong with checking out seaport village as well. a harbor tour might be fun for everyone as well so you can check out all the navy ships on 32nd street.
there is literally tons of stuff to do down here and most of it is family friendly.