We've been successful for the first time, after several disasters, one using a HFW recipe with Saltpetre. They were so salty they were inedible.
We used 'Supracure' bought from Weschenfelder website. All their cures/ mixes come with instructions and I think are reasonably priced. Ideal for small-scalers like us.
Their sausage mixes are great too, we like the 'Gold' and of course the 'Yorkshire'.
I bring the joints to the boil in cold water, drain it off then cook in foil in the oven, fantastic!