Your age range is very different than mine, as my daughter was 1 when I deployed. I got a webcam set and we did our best to have webcam "dates" but whether or not it worked was spotty since the bandwidth was a problem. I never could get through ON a holiday so we did things like Christmas 2 days early.
We still have flat mommy (a life sized cutout of me - sortof like the ones you see in movie rental places) in the playroom. Every morning Johanna would give flat Mommy a kiss, and that helped her be okay with giving me a kiss when I returned. I'd been very worried that she'd "forget" me since she was so young when I left.
I also made a lot of little DVDs with me reading stories so she could have Mommy any time she wanted.
It was tough being gone, but I sent home pictures, took videos and mailed them home, and worked hard to keep lines of communication open. You'll probably have a bit harder time because your children are old enough to grasp a major difference in time.
My DH didn't *need* the help, but we also had Grandparents come down to visit for prolonged periods of time to help with showering of extra affection.
I really haven't been to any military specific support boards. I will say that it seemed the separation was harder on the home front. You get into such a routine while deployed that you almost zone out. But at home there are constant reminders of the parent who isn't there right now. Be very good to yourself, and make sure you get some support from folks around you so you can get breaks from solo parent duty.