I know I'm a bit late to the party but I've just got COD4 and while the single player doesn't grab me I'm loving the MP, its just I'm rubbish at it 
I know with any game like this theres no substitute for practice but does anyone have any general tips that might help such as what sensitivity to use, which weapon to start off with, perks to use, links to decent guides etc.?
Any help would be great. Cheers.

I know with any game like this theres no substitute for practice but does anyone have any general tips that might help such as what sensitivity to use, which weapon to start off with, perks to use, links to decent guides etc.?
Any help would be great. Cheers.