Most simply brining allows meat and fish to retain moisture as they cook.
Turkey, chicken, pork, whole fish, and fish steaks all take very well to brining.
Turkey should be brined overnight.
Chicken for 4 hours.
Meat and fish steaks need only about 30 minutes.
A simple brine: ½ cup kosher salt and ¼ cup sugar per 6 cups of water.
Brines can be as complex as you desire with many spices and aromatics. It’s best to start simple perhaps with a chicken and gradually work your way up to more and more complex brines.