You could find a lot of specfic ski advice here:
http://www.boards.ie/vbulletin/showthread.php?t=2055046273&page=7
I have done Italy and Austria with the family. I would definitely recommend a return to Austria, no one does it better than them for kids and lessons.
1. Austria has all day lessons - this is REAL important with the kiddies as its probably the only time away from them you will get on your holiday! If they already do creche, then they will take to the austrian ski schools like a duck to water.
2. Pick a resort where the school meeting point is very close to your hotel/apartment. nothing worse than having to take several lifts or buses to get there. Think no hills.
3. Get your ski gear from a place that is also close to the school meeting point. Wait unitll you get there, find out the lie of the land (literally hills suck with kids), then buy all your gear when you know what place is easiest.
4. Creche, playarea, pools etc are all icing on the cake if you get the first 3 right. Kids love skiing, they might complain about the early start - but get them to the place, drop them off - and never look back. The austrian teacher gave out to me when i came back the first day at lunch to check on my kid - and she was right!
5. Overpack for the kids in terms of weather. Hats, gloves, scarves, neck warmers, proper ski suits/pants... dont skimp on them - they will be miserable. have two pairs minimum of everything. if it aint wet its sweaty...