This is a movie for the entire family. May be a bit scary for those under 5. The experience in IMAX 3D is superb and if it's available at your theater is it worth the couple extra bucks. Don't miss this one in the theater, as it will not be as amazing at home.
This is a beautiful movie on several levels. It is gorgeously rendered. The 3D techniques are well done (find a theater with the 3D system - it really improves the experience), and the character development is superb. Only Pixar/Disney could do a 7 minute montage with nothing but music.
You will probably need to discuss some of the themes of loss and accountability with your kids - but you both will profit from this.
Lots of fun and a tear or two make for a great movie.