I usually start by rifling through the dried beans, keeping an eye out for any stones or strugglers and discarding them. Rinse the beans and drain.
Add the rinsed beans to a pot along with 2-3 quarts of cold water. You'll typically want the water level to be 2" above the dried beans, so feel free to eyeball it. Add the roughly chopped onion and 2-3 tablespoons of lard (or bacon drippings).
Cover and bring to a boil, then reduce heat to a simmer and let 'em cook! I usually start taking bites around the 90 minute mark. If they are hard and grainy then give them a bit longer. Note: starting with the water level 2" above the dried beans will usually ensure the beans stay submerged throughout the cook, but if the water level gets low and the beans are exposed feel free to add a bit more.
Once the beans are soft and mushy you can add the salt. I usually add a heaping teaspoon at this point along with a generous pinch of Mexican oregano (optional). Let them cook for another 15 minutes and then take a final taste for seasoning. I added more salt at this point, so that is about 2.5 teaspoons total.
Note: the salt level is negotiable! If you want them to be edible out of the pot you'll probably need somewhere between 2-3 teaspoons total. But it also depends on how you'll be using them -- for example when I use the beans for soup I don't salt them as much during the cook as this will leave some leeway down the road.
You'll end up with 6 cups of cooked beans and some leftover broth. Sometimes I will portion them into individual baggies containing a single cups of beans and broth, but for this batch I used two quart-sized jars. Each jar got 3 cups of cooked beans and a single cup of broth.
You can store the cooked beans in the fridge where they will keep for a few days, or you can store them in the freezer where they will keep for significantly longer.