Heres some tips my brother uses for his....
Use Pecan wood. Seems to really have the best flavor out of all of the ones we have tried. Try not to use pieces that have Bark as it can leave an off or bitter flavor.
Use the smoke stack valve on top to control temp. If you need to get the fire blazing the sliding door in the firebox is good but use the top smokestack cover to make the little adjustments.
By all means use the water on the bottom idea....for an extra touch fill it with beer and some garlic.
SLow and long is the way to go and thr rough rule of thumb is one hour for every pound. For super long smoking times not a bad idea to rotate the food 1/2 way through the cook. Also keep in mind food cloer to the smoke box willl cook hotter while food placed by the stack will cook cooler.
Some Fun items to do when cooking..
Smoked Onion-Place a whole sweet maui onion on the grill. The outside will turn black as coal but the inside will cook slowly and gently.
Smoked Cheese-Use a Cedar Plank and cut various blocks of cheese on top. Cheddars and Swisses work very well. Get some crackers ready because when you take it right out of the smoker its still semi soft and spreads very easily.
For those who love to BBQ the smoker is a dream come true as it prolongs the BBQ process ten fold.
One item we make occasionally that is unusual but delicious is something we call Tokyo Tacos.
Its basically a cut of Round Eye-which is a cut of meat that is tough as hell but round. Smoke the hell out of it and then slice as thin as possible. I use a meat slicer but a sharp knife should do the trick. When youve got your thin slice, top with some grated daikon, and a small drizzle of soy sauce and a squeeze of lime. Its a very interesting taste with the coolness of the daikon contrasting with the smoke of the meat and the tartness of the juice and the salt of soy.