I can't speak as a father or a daddy but I can speak at length about being the child of an active duty member.
The best thing you can do is stay in touch with your kids as much as you can, getting letters (note: Not E-mails) from my dad was one of the best things a child can experience, pictures and of course..the presents you bring when you get back (a must at any age). I got phone calls at Christmas when dad was in the gulf or Europe (which was no small gesture given the technology of the day) and great brown paper packages (indeed, tied up with string) for the birthdays, which, regardless of what was inside, made me and everyone in the family happy. It's really easy now compared when I was a kid, so I'd expect that you shouldn't be out of touch from your kids unless you absolutely have to.
Get them interested in your career, let them know exactly what you're doing, make them proud of it and you'd be surprised how well kids will respond; yes it can at times border on propaganda, but as long as they're not militant about it, it gives them an immensely good feeling to be able to go to school and tell the other kids what their dad does. That's extremely good advice, from the childs perspective. There will be tears on your departure regardless of what you do, but you can make damn sure they're proud of dad and you'll see that over the years they'll become fine military brats: ready to move at a moments notice, immensely proud of dad and supportive and protective of mum.
Get them involved with other families in your situation, 25 years later my family is still in constant communication with the young couples they met on their first posting because of the bond that was formed as a result of the support the wives and children (to a lesser extent) offered each other while the dads were away at sea for 6 months to a year.
And to add my own personal observation, don't disparage the military or your job infront of the wife and kids, it will only make them hate it and it will not bode well on the home front while you're deployed.
On your own part I can't comment beyond what gunner said about having a stiff upper lip, that's the only thing my dad ever said more or less.