For general purposes I just take my trusty saw to the nearest tree that needs trimming and lope off a branch about 1"- 1.75 in dia, cut to fit the wood box and smoke away. I will say the left over wood does dry somewhat but is still used. BArk bugs everything goes in the fire! I am using oak and am not particular as to what species.
Smoked 240 lbs of meat for my 4th of July bash with no complaints or left overs.
That said I do use dried wood such as mesquite, cherry, maple etc on other "dishes" because I have to buy them at the store.
Try it sometime on a butt.
This is my opinion and taste!