I'm getting to your post a little late, but I thought I would share a couple of things I've found useful during past deployments and this one (my Dh left yesterday).
First, we always do a countdown. Of course we don't really know when he'll be home, but it's supposed to be a year so I have a plaque that says "Daddy comes home in" and changeable numbers that hang on hooks. I've also heard of people filling a jar with 365 hershey kisses so their child gets a kiss from daddy every night and as the jar empties it gets closer to when he comes home (this is easier to fudge, you can add or take away as you need to).
Something else that helps me is to get involved with our FRG. I see your Dh is a Marine, but I assume you have something like that, a family support group. I have found that I actually get info. faster that way because it comes straight from the commander, I usually find out things before my DH does.
As someone else mentioned, our school has a group that kids can attend to help with any family changes, they do crafts, talk, hang out.
Read your post's newspaper! I can't stress this enough. I just can't believe the number of people that just leave it outside until it gets thrown away! It's a wealth of information. Some places offer free childcare on the first Sat. of the month for parents of deployed children, free bowling, free crafts, etc. The newspaper is the best way to find out what resources are available.
You are doing a great job preparing yourself ahead of time

, you are really making things easier on yourself by doing this.