I have tried this recipe from the book 'Charcuterie' and it makes truly excellent salami, approx. 1/3 hard pork back fat, 1/3 pork shoulder, and 1/3 venison.
It sounds all quite complicated but the principle of salami making is that the meat mixture is seasoned with herbs and spices, the correct amount of salt (including some 'curing salt') is added, the mixture is ground, the fermentation bacteria are mixed in. Basically so-called 'good bacteria' quite similar to those found in health food/yoghurt products. That mixture is cured in the refrigerator for approx. 48 hours, to allow the salt to cure the meat and penetrate everywhere so that helps with preservation.
Then the sausages are made using artificial or natural casings; and hung for some 48 hours to 'ferment' at room temperature. This is where the 'good bacteria' do their work and lower the Ph and increase the acidity.
Finally the sausages are hung to dry in a cool place such as a garage (winter) or a more fancy custom built drying room or simply on an open rack in the refrigerator.
After some 3 weeks the weight will have dropped by some 30% and your product is ready.
If you get any bad smells or coloured moults during this process something has gone wrong, but a bloom of white moults on the outside generally is fine.
The curing salt (I use all purpose curing salt from Sausage Making Equipment, Ingredients, gifts, recipes and ideas... ) is really necessary as too many people have died from eating salami that didn't have the correct preservation chemicals added.