Welcome to TT!! I'm fairly new to this site but I posted a similar question a couple of months ago and I received pretty good tips. We are a GS family from VA and just moved to Stuttgart a little over 3 weeks ago (my husband has been traveling to Germany for years now though). We are currently staying in a hotel with our 2 kids and one dog, it's pretty cramped but we are making the best of it. I wasn't prepared for this cold weather we are having so it wouldn't hurt to pack a jacket for you and every member of your family... just in case, the weather is pretty unpredictable here so I've been told. I started searching for houses while still back in the states but like someone mentioned above, there's nothing you can really do until you get here. We started house hunting last week and so far we've seen about 7 houses. We are pretty laid back and willing to compromise but because we need a large yard for our dog and kids, it seems that our search will take longer than expected. There are a few sites you can look at and get an idea of what's out there. Stuttgart is part of the Baden-Wuerttemberg state and there are several districts within the state, one of them being Stuttgart, then there's Boblingen, Esslingen, Waiblingen (which is part of Rems-murr) and Ludwigsburg. There are a few more but the ones I mentioned are the closest to all American bases here in Stuttgart or I should say that those districts are the ones that are directly attached to the middle (Stuttgart). You can search on http://www.immobilienscout24.de
and have google translate the page for you. You can also search http://www.stuttgartrealtors.com/
Those pages are pretty helpful, the one I used the most is Immobilien Scout 24 because it has a large amount of homes listed. And yes, agents do charge up to 3x the rent for their fees... which is silly because all they really do is open the door and show you around, when you sign a contract, and something goes wrong with the house or you need something, you deal directly with the landlord. The agent does not work as property manager like they do in the states. But since your husband is a contractor, it might be in the contract that he will get reimbursed for such fee, maybe a small portion of it... you might want to look into that.
Good luck and I wish you the best of your move, it can pretty stressful but it's worth it ... don't hesitate to ask any question