How do I make sure that the meat cooks well and yet stays juicy on a bbq?

Common noob mistakes:

Cooking things too long. Meat dries out when it's cooked to too high an internal temperature. That's the whole thing, and it's true no matter how you cook something. If you like your meat to be completely devoid of pink inside, it will be dry. No avoiding it. Find out what's a good temperature for the doneness you desire, and use an instant-read thermometer to find out when you get there. You will also find that some cuts of meat want more cooking than others. A skirt steak wants hardly any cooking because it dries out easily. A New York strip, with good fat marbling, can withstand more cooking because it has that nice fat to keep things moist.

Cooking with too much heat or too little. When the heat's too high, you burn the outside before the middle can get to the temperature you want. If it's too low, you never really get a good sear on the outside, and miss out on much of the grilled food experience. And you'll need to learn to tailor your heat to the needs of what you're cooking--fish typically needs less than chicken, which needs less than beef or lamb.

Putting the meat on too early. You need to wait for the charcoal to ash over and stop flaming. If you don't wait for the coals to get right, you run a much greater risk of flare-ups and scorched food, not to mention off flavors from unburned wood or fillers in your charcoal. This is a non-issue with gas grills.

Not preheating the grate. You need to put the grill grate over the coals as soon as you can so it preheats well. If your grate isn't preheated, you won't get grill marks, and your meat is more likely to stick. You need to do this if you have a gas grill too--maybe more so, since they typically don't get as hot.

I'd recommend that you find a basic book about grilling. Any of Steven Raichlen's books will give you the general tips on how to do things. I'm not wild about his overuse of rubs and sauces--I think they're totally unnecessary most of the time--but he does know his way around a fire and a grill grate.

However, if you want your meat well-done, be prepared to eat a lot of dry (and likely tough) meat. Your only option at that point is to switch to low-and-slow techniques that cook things like pork shoulder for a really long time at a low temperature (traditional barbecue). The meat gets fully cooked, but because it has a lot of fat and connective tissue to render, retains a moist mouthfeel. But this isn't grilling, per se, and takes many hours.

Like anything else, barbecue and grilling are all about the right tool for the right job. That means using the right amount of heat, and the right type of heat for what you are cooking.

For example:

Steaks, chops, and boneless chicken can be cooked over direct, medium-high to high heat. Pound out your chicken pieces so they are of even thickness (and therefore will cook evenly). Even if you are cooking over direct heat, it is also best to have a zone of low, indirect heat in your cooking area. You can move your meat to that zone to finish, or if it is cooking too quickly. This brings up another key point -- if you are cooking hot and fast, keep a close eye on it! At high heat over a grill, the difference between tender and juicy and shoe leather-like can be a one-minute flare-up. You want to be there in case you need to address a grill that is running too hot or flaming up (keep some salt on hand to suppress fires).

Fish filets are very gentle (not including tuna steaks in this discussion), so they need to be handled gently. Get yourself a grilling plank to protect your fish from the harsh radiant heat from your grill. A quick Google search will bring up plenty of resources on how to use it.

Chicken (or other poultry) on the bone is best cooked with indirect heat. Given the heterogeneity of thicknesses and materials in, for example, a chicken thigh, you want to apply ambient heat over a longer period of time.

Finally, there are the barbecue meats -- ribs, brisket, pork shoulder, chuck roasts. These need to be cooked slowly on indirect heat at low temperatures (around 225-300 degrees Fahrenheit). The exception here is baby back ribs, which can be cooked over direct heat, so long as you keep the level of heat fairly low, and flip them frequently. All these meats have lots of connective tissues and fats that need to be rendered to achieve tenderness. As a result, you need to get the meats up to much higher internal temperatures, when compared to steaks, chops, chicken, and fish.

So be mindful of your tools with regards to what you are cooking, and beware the compulsion to overcook your meat. Keep those things in mind, and you should be fine.

If you want some good resources, check out these websites that I frequent:

• The Virtual Weber Bulletin Board: http://tvwbb.com
• BBQ Brethren: http://bbq-brethren.com

Both sites are forum-driven, and you'll find loads of recipes and helpful folks (particularly in the former site).

Good luck, and happy cooking!

There are some great responses here but no one has mentioned brining, yet. Put simply, this involves putting meat in a water/salt mixture for an extended period of time.

There are a couple of things that happen when you do this. First, nature likes things to be in balance. So the cells in the meat will actually expel some water and pull in salt (along with some of the other flavorings in your brine mixture). Second, salt holds about 3 times its weight in water and causes other chemical reactions that help trap water during cooking. The end result is a significant boost in moisture.

Of course, the tradeoff is the food can sometimes taste fairly salty but, if done right, this saltiness is easily overpowered by the juicy deliciousness of your end product.

EDIT:

One pointer I forgot to mention, when brining it can be tough to penetrate beyond the outer centimeter or so of your food. One technique to overcome this is to inject the brine.

In many cases, brining is truly like a "secret weapon" for keeping things juicy.

I try to get my grills good and hot before I put the meat on. This way the outer portion is seared which causes the pores of the meat to tighten up and thus keeping the moisture on the inside. I find this works well for almost everything except fish.

My new BBQ is equipped with an infrared grill which is awesome for this. I can sear the meat in 1-2 minutes and then move it off the intense heat to finish cooking slowly.