The thing about 'eat when you're hungry' is that when your body goes into ketosis, this acts as a natural appetite suppressant, and you simply won't be hungry.
Personally I don't think Pig to Twig is really strict enough in the beginning. I think it would be good for you and your DH to do something like Atkins or Harcombe, with an initial strict phase, to make sure that you get into ketosis.
And once you get your head round it, you won't have to do much counting.
Basically, for an induction type of day, following Atkins, you're looking to eat protein and fat, with minimal carbs (20g). So, bacon and eggs, scrambled eggs, poached eggs, etc are all good breakfast choices. (P2T breakfast on day one is 2 fried eggs and 4 rashers of bacon, which I have always thought was far too much!)
For lunch, some protein with a salad (with an oil-based dressing), and then an evening meal of protein with low-carb veg, e.g. broccoli, cauliflower, leeks spinach, cabbage, dourgettes.
The list of carb counts kotinka posted is really helpful - and can help you to get your head round quantities, so that you don't have to count carbs. Take celery - you could have 20 sticks of celery and still not have consumed 20g of carbs! And if half a cup of iceberg lettuce is 0.2g of carbs, you can eat an awful lot of salad!