Grilling over a wood or mesquite charcoal fire is one of my favorite ways to prepare dinner.
Grilling is a form of cooking that involves dry heat. The high temperature of wood and charcoal (600*F - 750*F) causes the water content of the food to evaporate quickly, causing the item to caramelize, develop a crispy texture, and take on a smoky flavor.
Whether you grill over a fire or on a gas grill, the process is the same: Start with clean grill grates (no need to revisit your last grilled meal!); lightly brush the cooking surface with oil to prevent the food won't stick; and heat the grate completely before putting food on it.
If you are building a fire, start it early and allow the flame to burn down to coals that radiate deep heat; this could take up to 2 hours. Keep in mind that your coals will continue to change temperature as you cook. Grilling over coals requires a bit of flexibility!
If you are using a gas grill, the warming rack above the grill grates is an excellent place to cook salmon filets, whole fish, split bone-in chickens, tied lamb legs and any other ingredient that doesn't require direct contact with a hot grill. This section of the grill becomes a natural heat convection area when the cover is down, allowing the food to brown evenly with requiring rotation.
Lightly oil and season your ingredients before placing them on the grill. As the food begins to brown, rotate the items with a pair of tongs to help them cook and color evenly. Perfectly cross-hatch grill marks are a nice touch to a cut of meat, but certainly not essential. Food on the grill can dry out or burn quickly, so monitor items over direct high heat closely.
If your fire or charcoal grill is large enough, you can create different heat zones to allow for rotating various ingredients from high to medium to low heat. This can be accomplished by moving the coals around in piles, after they have burned down.