I am an army wife and really like it. Hubby retired after 20 years infantry, luckily he still has good knees. I really miss the army life as being a retiree is a lot different.
I really like Margie M's answer. She summed up the life pretty well. You do have to learn to be independent and do everything on your own but do learn to include him in your family life when he is home and try to stay with the same routine of life for your kids but learn to include your husband in that routine when he is home.
We had all our kids during army life. When he retired the oldest was in 6th grade, 2nd one 3rd grade, and youngest was 4. He does seem closer to the youngest because he has spent more time with him as he didn't go to the field much at all when youngest was a baby because he was having surgeries and on medical profile for a year then was on retirement status and undeployable the following year so he was home and we had to adjust to the family life of having him home every night for dinner which we didn't have often for 10 years. The older 2 he was gone a lot, being infantry they are gone all the time, even if they aren't deployed somewhere they are training and even when in garrison he would get home at 9 or 10 pm and the kids were asleep.
I enjoyed the moving every 3 years, seeing the country, and meeting new friends. I have kept in contact with most of my army friends through the years, even the ones I met 19 years ago when we got married. That is the part I miss the most. There is nothing like military wives who understand your life that only those that live through it can know.
I guess I transitioned to the life better than most. My dad is a truck driver and was gone 6 weeks at a time most of my life so my mom pretty much raised us and still managed to have a close relationship with dad.
You have to be a strong person to make it through the military life. Get involved in family support groups so you aren't alone and make friends so you have a support group. Find a church wherever you go. Don't hesitate to ask questions especially about the resources available on your base. When things go wrong in housing, know how to get in touch with maintenance and use the MWR--they have all kinds of things you can rent or borrow real cheap, like bounce houses for your kids bday parties, lawn mowers, boats, jet ski's, campers, and all kinds of stuff.
Whatever you do, if this is something your husband really wants to do, support him and don't ever make him feel guilty for being gone while you are feeling all alone at home taking care of everything and raising the kids. Just keep in mind that he does have a job and is paying the bills.
After hubby retired he got a good job but worked the 3pm-11pm shift and worked all weekends and 7 days a week most of the time. I will tell you that shift is harder than the military life because the kids never get to see him except a few hours on Saturday morning before he goes to work and during their summer break off school. After 6 years of that shift he recently got on dayshift and now the oldest is in college, 2nd child is 16, and youngest is 11. I can tell he feels sad that the kids have grown up and he missed out on so much of their lives but we did cherish our few hours of family time on Saturday mornings.
We are still adjusting to him actually being home every night now, have to think more of what to fix for dinner and make sure he knows what is going on with the schedule of life as our kids are involved in sports and youth activities at church.
So you see it doesn't matter if you are military or civilian, you can end up raising your kids a lot on your own and learn to take care of everything on your own. Life doesn't always go the way we expect them to. With the economy of so many people out of work I feel blessed. My husband always made it a priority to support his family the best he could and got to work in fields that he enjoys. He loved the army and loves his job now. Not many people can say they love their jobs and he has been blessed to have 2 great career jobs in his life that he has truly enjoyed and I know a lot of his success was because he had his family at home supporting him and I did everything I could to take care of things on my own as much as I could so he didn't have to deal with stressful things when he came home and could relax and enjoy us as a family. I would even let him go fishing and hunting on his first weekend home if he wanted to. Something about getting in the woods or on the water taking time for himself would calm the stresses of work from his mind.
We all need that type of downtime and encourage him to watch the kids so you can go out and pamper yourself alone too. Go shopping or get a pedicure on your own. Usually if you give him his down time he won't mind giving you a few hours of time to yourself. Some bases actually have daycare programs that will watch your kids for free every other Saturday if your spouse is deployed so make sure you find out what is available to wherever you get stationed and find out what is available to you and don't be afraid to use them.
With his knee problem I don't recommend an infantry unit. Hopefully he will get something else where he isn't humping 80-100 lb rucksacks up mountains or big hills all the time.