You need to know what your DH taxable income is b/c it will ask you for that in e-tax and this will determine some other things like the Medicare Levy Surcharge etc.... My DH only receives PAYG income & some interest income and that is it, so it was easy for me to input that. However, if your DH is self-employed or has multiple income sources it will be trickier. For his tax return, you will still need your taxable income as well.
If you run into difficulty give the help phone number a call, they can talk you through alot of things. GL