Sir, you can start a snot storm with a question like that.
I like hickory, some of our Texas brothers will say mesquite only. Soo whatever your preference.
Try hickory. Next weekend, try mesquite. But both times, post your results and what you learned.
You'll read about the 3-2-1 technique. 3 hours in the smoke chamber (running 230ish) till the meat starts pulling back from the bone, spraying with apple juice if you don't mop (by the way, check recipe section for mops and such), then wrap in foil for 2 hours, then back in smoke unwrapped for an hour and some mopping. Bones will fall off (if thats how you like them, if not, don't wrap.
This is for spares. BBacks will be shorter, maybe 2-2-1 method.
But experimenting is half the fun.
Good luck, and again, post your results!