Poultry is often brined before you buy it, just look on the label for something mentioning a 5-10% solution or some such. You typically have to pay more for chicken that isn't brined.
For baking bread salt helps the gluten bind together which helps trap CO2 in the bread which helps it rise.
Soaking for a day or so in a brine solution can definitely help make many cuts of meat taste better, especially thick ones like leg of lamb, turkeys, roasts, etc...
For steaks I like doing a quick dry aging where I sprinkle salt and pepper on them and then let them sit on a rack in the refrigerator for a day or two before cooking them. It really brings out the flavor.