From a Freeper who has been married for 17 years, and got married at 30 to a woman of 29, also both with good jobs, let me offer some words of advice:
1) Be positive about it and expect things will work out.
2) Your greatest joy in life will be your children. We have three now and at age 47 I can think of nothing that is more important to me, except my country and my faith. Don't cheat yourself because you don't think you will be able to afford them.
3) If you have to, move to a lower cost-of-living area when your wife stops working to raise the children. [This happened to us with the birth of our second -- we moved from high-rent Menlo Park CA to lower-rent San Diego.]
4) Finally, don't let the financial planners and Money Magazine scare you about the cost of raising children. They will have you fretting about the need to put $5K away each year to pay for their college or some such nonsense. Just work hard and trust that this will all work out. It did for our parents -- mine didn't do any financial planning, yet we all went to college -- and it will for you, too.
Good luck and God bless.
I'm amazed at how much the cost of living varies from one area to the other. I'm in Boston right now. I have to make twice what I would make if I lived in North Carolina. Yet salaries aren't any higher in my field. There are websites where you can go and get cost-of-living information by state and city. It's sobering.