Hope you realise your going from a puddy tat to a tiger. The 1D MK IV a completely different beast. My advice is definitely read the manual, and enjoy you new purchase when you get it
i have noticed that you come from Fareham thats where i grew up
One question though why have you gone for the 1D MKIV? Did you consider other options and what do you like taking photo's of? Just interested, as most people might have gone to a 60D, 7D or full frame