Beginners FAQ on sausage making, meat curing etc may often be found at the head of each relevant section, but here is the place to ask experienced users for advice if you are still stuck or need more information...we're here to help!
Eskimo Joe - you simply multiple each % by the total mass of sausage you want to make. For example, to end up with 1kg you would need: 500g pork shoulder (1000g * 50%) 250g pork belly 50g Fresh Leeks 25g seasoning 65g Rusk 65g water
(however something seems to be missing as you only have 95.5% listed)
Pigs are magical creatures.... they turn vegetables into BACON!!