Wood burns efficiently at one speed. You don't need a big piece of wood to get a good smoke, in fact, when it comes to making "thin blue smoke," bigger is NOT necessarily better. The key is to have small amounts of wood burn efficiently, so you get sweet smoke flavor, and not bitter, over-smoked flavor.
I use charcoal for heat on my WSM, and mix some wood chunks in, using the Minion method. If needed, I add small amounts of wood chunks, so I can still smell wood smoke, but not too much at a time, so I don't get thick white smoke.
Certain principles apply whether you use a stick burner, or use charcoal and chunks. Either way, you want mostly hot coals for heat, and small amounts of wood for smoke.
I follow my nose. If I smell wood smoke, I leave it alone, if I don't I add a few wood chunks, right on top of some red-hot coals. IMO, the best smoke is smelled, not seen.
As for the kind of wood to use, that is subjective. I like pecan for lots of meats, apple for pork, and oak for beef. But, honestly, I've used the "wrong" wood from time-to-time, and didn't find any fault in the meat. The only wood I don't like for long cooks is Mesquite. I like it for steaks, but it is too strong for my tastes on BBQ. Personal preference.