Dinny, there is no need to count points or your GI index etc unless you want to follow a specific diet.
Just stick to the basics and you'll be fine.
No bad snacks, only sncak if you've quenched your thirst and waited 5 minutes (it really does help, plus if you drink water your mouth tastes neutral and the thought of adding anythign sweet to it is quite off-putting).
All carbs, or as many as possible to be good crabs, not empty things like crisps and cake and white bread.
Three decent meals a day.
Plan your food, tomorrow I've promised to do burgers for the DC's but am going to do home-made oven chips and will pick up some granary rolls for me today so I can still have burgers just won't be fucking up the whole diet, If I know I'm going to be eating cake at MiL's for example, I'd make sure everything else was good substantial food, if I am eating lasagne and jacket spud, I wouldn't try not to have any other carbs during the day etc.
Exercise, a small amount, just to get your metabolism kicking in, it can be chair exercises, doesn't have to be running or something, for me it's just getting one less bus a day and walking instead.