Im about to put a pork shoulder in the smoker. Where should I stick my mavrick probe? Will it be a problem if I stick it through the fat cap?
You can go thru the fat cap.
Make sure you are in solid meat.
Don't touch the bone and don't let the probe tip end
in the soft tissue (collagen) of the butt.
Do as CRG said. When it seems done, try the probe in a few other places.
I generally place my in the deepest part of the butt. If it is bone-in just behind the shoulder blade.
Towards the end of the following article, it gives suggestions on thermometer placement for various cuts of meat.
When Is Meat Done (http://www.susanminor.org/forums/showthread.php?485-When-Is-Meat-Done-Pt.-1)