Can I salt beans before they are cooked?

I do it both ways (salt at the beginning and the end) depending on the dish. For a pot of Mexican style (simply boiled beans) I usually salt at the end but for red beans and rice and some other dishes I salt before hand. I find either one works just fine.

I always salt after the beans are soft, but before they are done. I have some Rio Zape simmering right now. Just salted them after 45 minutes of cooking time. I have friends and colleagues who swear that's not necessary, but that's how my momma taught me, and tho I have tried the other, even when the beans are fresh, they don't get soft. So....

I read the recipe - in this particular one, Merrill is using a fast parboil method with navy beans which is definitely a tried and true way of doing it. Adding salt to most of the common bean varieties (white/Navy, cannellini, kidney, pinto, cranberry, etc.) will not keep them from softening. In fact, Cook's Illustrated tested it and found that it helps improve the texture of the cooked beans - read about it here: http://tinyurl.com/kxzmf9u (Article at TheKitchn)

I make beans every week, and I salt them right away. Never have a problem. I've found that they are only tough if they are very old.

I salt after. Likewise with acid (tomato). Adding early will keep the beans tough - which is not desirable.