Source: http://www.firepit-and-grilling-guru.com/smoking-wood.html
 
Cooking with real wood smoke from smoking wood or a firewood fire is the ultimate in outdoor cooking. The flavors and aromas several varieties of savory aromatic woods can greatly enhance your raw ingredients. As I've mentioned elsewhere and you probably already know, the most widely available and familiar wood types for smoking are mesquite and hickory. However, wood types don't end there! Just about any wood you can cook with can also be used as chips or chunks as a source of aromatic smoke. The total list is vast, but below you will find a list of many of the most common, and best, woods which you can find and use to smoke your food, either on a charcoal grill, smoker or even in a smoking box on your gas grill. You will see that many of these types are the same woods which are great for cooking over if you are cooking over a real wood fire. Several of these types can be found in grill specialty shops in your local area but others are also available online.

There are several ways to get real wood smoke flavor into your food. The most common ways are listed below but also see my Smoking Box Cooking page for instructions on how to use smoking woods:
W. Justin Sealy
Area Forestry Teacher
Georgia Department of Education
229.328.8263