Always use kosher salt. And keep in mind different brands have different structures. We use Diamond Crystal in the Peel household. Mortons is the other most common brand in the US. Cook's Illustrated did a study comparison and Diamond Crystal has a larger structure so it contains less salt than an equal volume of Mortons. It doesn't matter which brand you use, it matters that you are consistent in your cooking so you get a feel for how much of your preferred kosher salt is the right amount when seasoning food. I don't recommend table salt for brining, it will cause the meat to be too salty.