My husband is in the Army. I agree with @erichw1504 that the Air Force seems to be the most family oriented (from my experience with other military families). As far as what effect the military life will have on your wife, a lot of it depends on her. As it stands right now, my husband and I just celebrated our 2nd anniversary and have only spent half of it together. Most of the couples I know have only spent about half of their marriage together in the past 8 years or so.
Separation: There will be time apart. If you enlist, she won’t be able to join you until after you complete your basic training and job training (depending on the length). She might be able to join you at the location of your job training if it’s going to be for more than 6 months. If it’s less than 6 months, she won’t be able to join you (at least not with the military paying for the move and a place to stay). That will be true for any future training you go through as well (which there will be other training things you will have to go to. Deployment length depends on which branch of the military you go into and what your job is. Right now, typical deployments are about 6 months for Navy and Air Force, 6–9 months for Marines, and 12 months for Army. Each deployment will be different and communication during deployment really depends on where you go and what you are doing. My husband is currently deployed to a location where he can get internet access in his room. We get to talk on almost a daily basis (almost because there are days when he is too busy/tired to get online and other days when the internet is out for various reason). Right now, there are frequent deployments for most people in the military. Depending on which branch would depend on how often. I’m not 100% sure what the down time is in between deployments, but for the Army right now it’s 12 months gone, 12 months home, then 12 months gone again (so basically a year in between deployments). I say right now, because they are hoping to change that (to shorter deployments and longer in between them). I believe most of the other branches have something similar (to where the time off between deployments is equal to the length of the deployment). If your wife is an independent person, she can use the time you guys are apart to really explore the things she likes. She can take classes to further her career or just to explore her hobbies. Also, the military could technically call you in at anytime, even on your “days off”. If you want to take a week (7 days) of vacation, it will actually cost 7 days of your leave because technically you don’t have days off (which is why I put that in quotes up above). Your normal work day could end up being 12+ hours long depending on the unit you are in and your job.
Worry/stress: Deployments can be very stressful. You develop a new fear (of soldiers in the Class A’s coming to your door). She will worry about your safety and if you are going to make it home. One of the best things she can do if you deploy is to stop watching the news. Watching the news and hearing about a bombing here or a bombing there will just cause more stress and anxiety. (I am only putting this in here in case she has any kind of anxiety disorder, because deployments can make it worse.)
Communication: Communication is important in all relationships, but because you will have times when you have to make big decisions in a short time (or when the military will make those decisions for you), it’s important that the two of you are able to talk about those things. You will want to include her in as many decisions as you can because sometimes it really sucks knowing you have so little say in what happens next in your life.
Career: Depending on what your wife does, that may or may not transfer to each location you are sent to. If she works for a company that has locations in a lot of places, she may be able to transfer (if you are lucky enough to be sent somewhere that her place has a location). Otherwise, she will have to find a new job at a new company each time you move.
Travel/moving: You may have to move every 2–3 years depending on your job and were it is needed. There are some families that have stayed in the same place for 6+ years though, so you may not have to move as often. There is also the possibility of you getting an unaccompanied tour to Korea (or a few other overseas locations). It would be a one year tour that the military would not pay for your wife to go with you. If you are given one of those assignments, you could ask for the command to sponsor your wife and make it a family tour. If they do that, it would be at least a 2 year tour and the military would pay to move your family as well. The bright side of moving so often is if you end up in a place you hate, you most likely won’t be there long. You will have the opportunity to see things you probably never would have went to see otherwise. (For example when we were stationed in Texas, we went to see The Alamo and the Riverwalk in San Antonio. I don’t think we would have ever went there is we weren’t nearby.)
Planning/vacation: It’s really hard to plan things sometimes. In order for you to get time off, your command will have to approve it. This can make planning a vacation or just a special dinner rather difficult. On the bright side, you will get a decent amount of vacation time and in time, you will learn how to really plan vacations. Things are also almost constantly changing. What you hear today, may change tomorrow, so you have to be able to go with the flow in order to avoid stress. (This is a hard one for me because I am a planner. I’ve learned how to plan what I can and usually end up planning for multiple scenarios now so that I’m ready no matter what happens.)
Special occasions: You will miss special occasions. If you and your wife are flexible, you will learn that you can celebrate those special occasions on any day and realize that they don’t have to be celebrated on the actual day they occur. However, some families are unable to understand that and they let the missing of those occasions have an affect on their relationship.
Family: If you and your wife decide to have children, you both will have to realize that there will be times she may feel like a single parent (when you are away). I know some families that try to plan having kids around deployments, but in all honesty, right now that’s really hard to do (thanks to frequent deployments). Some plan to be there for the pregnancy and birth, but then end up getting send away and missing a lot of the first milestones. Others plan to miss the pregnancy and birth so that they are there for the first year. In addition to children, you have to realize that the military can send you anywhere in the world, so you may be moved far, far away from all of your friends and family. Your family will want you to visit (obviously) and sometimes families can tend to put a lot of pressure on the soldier and his spouse to be the ones doing all of the traveling (this is from my personal experience).
Healthcare: With the military, you will have Tricare for your health insurance. Sometimes Tricare can be a pain, but in all honesty, they really do take good care of the military and their families. I have not had any problems with getting the care I needed when I needed it. Depending on where you are stationed, you may be able to use military healthcare providers or you may use civilian healthcare providers.
That is most of the things I could think of off the top of my head. I think you should definitely talk to your wife about this idea to get her opinion. If you decide to talk to a recruiter, remember that they want you to join and they are going to try to sell it to you. If they promise anything, get it in writing, otherwise it may not happen. If you have any specific questions, I’d be happy to try to answer them.