How can we prepare to cope with one less income?

Q.

My wife and I, aged 27 and 29 respectively, have a combined income of $190k gross per annum. We currently have our mortgage at $330k with a house value of $520k and no other debt. We're considering investing but not sure what is the best approach as we would like to have children within the next year or so which will reduce our income to $80k. What investment options should we be considering in the next 12 to 18 months to maximize our current situation but not to have a negative impact once children arrive?

You need to put yourselves into as secure a position as possible so I suggest you use an offset account, if your lender offers it, and pour all your surplus funds into it. This will give you the highest effective after-tax return and at the same time give you maximum flexibility.