I've been tracking all our spending in iBank for years. (It's for mac only, but I know there are similarly good programs for PC as well, if that's what you have.) I treat our finances almost like a business...there's a budget that's specific by category, I track every transaction and the money we make by category, we go over our finances when they fall out of line with the budget, and we sit down every year to create the budget for the following year. It makes it much easier to have a conversation about finances if you have specifics ("It's only the 21st and we're already over budget for the month on groceries...let's talk about why that happened. Was it a one-time thing (we had a big party), or did we just lose track? What can we do to save money here?") Also, just like tracking calories, just tracking your finances can make you think twice before you buy something...and it puts your spending over time in living color so you can see how little spending habits add up over the month or year.
It sounds like your hubby is used to not having to worry about every-day spending, which is totally normal when you're making a comfortable living, and even more so if he's not the one actually managing the finances. His mindset hasn't caught up with your new reality, and having concrete information about how much money is coming in and how much is going out and where it's being spent can help him wrap his mind around the new numbers. Once you see how you're spending, it'll be easier to see where you can trim and what habits you can change.
It may cost some money to get a good program (iBank is around $60 - http://www.iggsoftware.com/ibank/ I've heard good things about www.Mint.com but haven't used it...that one's free!) and it takes some work to keep it all straight, but it's worth it in the long run. I usually spend 10-20 minutes every few days entering our receipts and checking our online accounts to see what's cleared and any transactions that I didn't get a receipt for. Like I said, I've been doing it for years, so it's just part of my routine now. It really helps us make decisions big and small...should we eat out tonight, or cook? can we afford a bike for the little one? are we saving?
Good luck!