I think the most important tip is to make sure you light the barbecue early and use plenty of charcoal and if you use anything to help get the fire going make sure it won't linger. Rule of thumb, if you can smel lit , you WILL taste it !
The reason to light it well in advance is so that the fire is well established and burnt down, no naked flames, that's why I say use plenty of charcoal a) you don't want to have to add more once you start cooking and of course b) you don't want it to go out !
Best cooking tip, CHEAT ! Stay away from British sausages, they contain so much fat they are a fire hazzard and will cause you nothing but heartache... Sausages need slow cooking and most Barbecues are too hot.
Chicken is great, again in the interst of speed and safety, pre cook them, I poach them in milk ahead of schedule then marinate them in a favourite sauce. Sneak them out onto the pit turn them a few times brushing them with spare sauce as you go.
Fish Barbecues well, Swordfish or Tuna Steaks,
As a starter King Prawns, I cook them in tin foil parcels , sprinkle the foil with salt, pepper and garlic salt, a few knows of butter and a sprinkle of lemon juice. Turn the parcels a couple of times and serve. I use cocktail sticks and a couple of good dipping sauces, a hot spicy tomato one is best.
Lots of salad dishes, dips and of course cold wine and beer.
I hope this helps and you get good Barbecue weather.
PS Keep one of those spray thye water bottles close just in case you get too much flame, of course a spray of beer works too and doesn't hurt the taste.