Meat for sausage: pork leg, belly, fatback (20-30% of total meat), you can also add some beef but no more than 10%. Mince (with large openings) part of the meat and all the fatback and chop the rest of the meat into nail-size pieces (eventually you can mince all but if you chop part of the meat the texture and taste are better).
Salt it (17g of salt per 1kg of meat in total) add mustard seeds, milled black pepper, smashed garlick and other spices you like (milled coriander, caraway, marjoram, laurel leaves, red pepper etc. - but these are not required).
Mix for at least 20 minutes in a large bowl (salt and garlick may sting your hands a bit). Take hog casings (previously washed) and fill them with meat:

You should smoke it no later than a day after (use alder wood or the one from fruit trees) or froze and boil to eat.
you can also make use of these videos:
http://www.youtube.com/watch?v=F5ZcKJwAC1Uhttp://www.youtube.com/watch?v=EEKOM4uXnDQ