Hey, I'm forty, with two young kids too! But my wife doesn't think I'm paranoid, she's just concerned about the time commitment and safety of some of my preparations. So I'm going to work on the wife angle.
First, I recommend against hiding things from her that she hasn't authorized. You need to do some convincing first. Then ask for blanket OKs for classes of items. Start with food and water. With two young kids, she's sure to see the wisdom of storing basic quantities of food and water. Check out the
FEMA website for basic preparedness. It shouldn't be too hard to convince her that it makes sense to have the basics like FEMA points out everyone should have. Get her to agree to those basics first.
All the while, keep pointing out how the main stream media explanations for high gas prices make no sense, but approaching (or being at) peak oil explains everything. Point out that the oil crisis of the 70s makes a lot more sense when you realize that US oil production peaked in 70-71. Point out the recent WSJ articles and various articles and editorials from the British newspapers talking about peak oil. If you're more left of center, point out Paul Krugman's commentaries in the NY Times talking about peak oil.
You have to build her up to the Hirsch report. Once you've made it to the Hirsch report, point out that Hirsh recently said that people he listens to think we could get $12-$15 gas. I think most Americans can understand that all Hell breaks loose in this country if we ever get to $12 per gallon gas.
In the mean time, make sure you do your share of the housework. My wife's biggest fear in all of this, besides the safety of the kids, is that she's in for menial drudgery for the rest of her life if things go south. It helps her a lot to know that her husband is willing to work hard to make it easier for her.