Hi Colin,
I got diagnosed beginning of december with type 1 so i'm not experienced but i can share my experience so far with you.
I currently inject my lantus same time every evening between 8-10 units depending on the morning readings because the main reason for it I believe is to ensure that your first reading in the morning is within the target range, whilst also providing little doses throughout the day.
I take novorapid after every meal, but this is because i find when i take it before meals it kicks in too quick and i experience quite alot of hypos. You will be in the honeymoon period which means working out how much instant insulin you need is difficult but it is generally only a small dose because your pancreas is still producing some insulin. I am working on the 20 carbs to 1 unit ratio but taking 5 units before meals sounds about right, generally I take 2/4/6 breakfast/lunch/tea.
You will no doubt have an appointment with a DSN soon and will also have the opportunity to see a dietician who can give you some basics. The Diabetetic Specialists are usually very helpful and make sure you write down any questions you have, I didn't do this the first 2 appointments and my mind went blank.
As for snack's I was told anything 10 carbs and under shouldn't affect your Blood Glucose Levels too much although this is quite difficult to find. (Cheese or Cooked Meat) have no carbs with a couple of crackers.
Hope this is of some help.
Steven