You have a smoker…need wood, but you don’t know which wood to use. I can help, lets start off with the most basic rule in smoking meat, do not use too much smoke wood. Keep the total amount of smoking wood in the range of two pounds per smoking session. This also can be approximated as three to four chunks. A closed fist sized chunk of wood is approximately half a pound. As an engineer I would recommend using a small scale and actually weighing your smoke wood and keeping track of how much you used and if you desire more or less on your next smoke. With experience and practice I have gotten comfortable using my hands and eyeballing it, to select the right amount of wood. Let the smoke wood be a crave-able layer of flavor, rather than the dominant taste in your dish.
Kruski’s smoking wood of choice is actually an easy ratio of apple and hickory wood. When smoking small items like baby back ribs [1# Apple to 1/2# hickory]
When smoking large hunks of meat like Pork Butt or Beef Brisket [1# Apple to 1# hickory].
Wood Sources 
The wood source I used for most of my early smoking years is actually packaged under the Weber brand name sold by Amazon in 5# bags that run about $13 shipped so about $2.60 per pound.
Apple Wood Chunks Hickory Wood Chunks
An alternative source I use for ordering larger portions of smoking wood online is Fruita. If you can get your box shipped to a commercial address (like your work) they toss in free wood. I recently ordered a 30 pound box of apple and a 15 pound box of hickory and the total cost per pound on this order was $1.73 per pound. Below is an picture of my latest haul
When in doubt, always use less wood.
Use wood that you trust, don’t smoke dinner for your friends and family using recycled furniture, pallets, or scrap wood that may contain mold, stains, oils, glues, or some potential of being chemically treated. Do not use woods that are heavy in sap or natural oils like pine, spruce, cedar, eucalyptus, etc.
If you want to experiment or if you happen to have a different mild fruit-wood on hand such as peach, cherry, or pecan go ahead and substitute it for the apple wood. On the stronger non-fruit woods if you have mesquite, walnut, or red oak they could be substituted for the hickory wood. I personally prefer to use apple and hickory and recommend this perfect combination strongly.
