IMHO, you cant hardly mess up a brine. put in it whatever you like. the main ingredient is salt. common ingredients in a brine are water, canning and pickling salt, or koshuer salt, or tenderizing salt, pickling spice, pickling salt, bay leaves, peppercorns, chopped oninons, minced garlic cloves or even sugar.
brines can be cooked or uncooked. if you should cook a brine, let it cool before you put the meat in. you want to brine it, not cook it.
once you have your brine made and you insert the meat it will likely float up. put a glass plate and some type of heavy object on the top of the plate to keep the meat submerged. the salt will kill bacteria and keep the meat from spoiling. when you have the meat/plate and weight(if nessacary) in place, cover with plastic wrap and refridgerate. brine times vary from a couple hours to days or even weeks depending on what your doing. i seen a corned beef recipe that takes 3 weeks.
as far as knowing how much salt you need, that depends on the amount of water. a general rule is 1 cup for each gallon of water. when i brine salmon, i put enough salt in until i can float an egg. then i add the rest of my spices. i put the salmon in and let it set over night in the fridge, and smoke it the following day.
if you do a google search im sure youll come up with allot of brine recipes too.
good luck in your quest for brines. when done properly your food will turn out delicious.