Just wanted to agree with jeffreydb, COMMUNICATION. Yes, it is that important.
Next month will be 17 years married, 15 of that during a Navy career. We lived together for a year or so before we married, which worked out well for us because we figured out most of that stuff before actual marriage. When we would have issues (back then), she would bitch to her friends while I was bitching to my mom. Finally, my mom said to me once, 'have you said any of this to her?' Duh. Light bulb.
I was gone a LOT during my marriage (still am), but we always made a point to talk as much as possible. I would actually take shit from other guys about it - 'what could you possibly have to talk to your wife about for 45 minutes?' Uh, how about I enjoy conversations with her?
If/when you have kids, you need to be on the same page about discipline and child-rearing type stuff. And while it might be hard when the kids are real little, you HAVE to make your spouse a priority. Your spouse always comes first. Always. You two were together before the kids, and God willing you will still be together after they are grown and gone.
Good luck to you.