First off, welcome to the board. I'm Jess (23), my DH is active duty Army.
Sadly, there aren't going to be many straight answers for your questions. Everything varies from base to base and job to job within the Army, so there is no cut and dry across the board answer. Some bases have nice housing, some don't. Some have plenty of open housing, others don't. Some of the schools may be wonderful, others may leave a bit to be desired.
When it comes to deployment, it depends on what job he does, what unit he gets stationed with and what their deployment schedule is, and what our military needs are at the time based on what is happening around the world. Some people get lucky and don't deploy often, others are gone 12 months out of every 24 for years at a time. Some jobs deploy more often than others.
As for you kids, I don't have any children of my own but one thing I know about children is that they adjust WAY better than adults most of the time. They will be able to make friends wherever they go and they will most likely be pretty resilient to everything that is going on.
Good Luck with everything. If there is one piece of advice I have for you, it would be this: learn to roll with the punches and be patient in getting answers for your questions. The Army doesn't tend to divulge information it doesn't deem necessary, even if it's something you want to know. There is a lot of red tape to get through to do just about anything, and if you drive yourself crazy wanting to know everything right away, you'll never be able to adjust.