Don't use any wood from conifer trees, such as pine, fur, spruce, redwood, cedar, and cypress. Also elm, eucalyptus, sassafras, sycamore, and sweet gum wood is unsuitable for smoking. I'm sure there are others. I stick with fruit and nut wood, plus alder and maple.
My cooking family - 48" Jambo Pit Clone, Blaz'n Grill Works Gridiron Pellet, Primo XL Ceramic, Weber 22" with Smokenator, Lynx 36" SS Grill, Lynx Wok Burner, Charbroil The Big Easy, Weston 36" Upright, Cambro 400, DigiQ DX2, Maverick ET732
PNWBA - CBJ
KCBS - CBJ