When identifying wood, it may only be necessary to determine if the wood is a hardwood or softwood. In other cases determining if it is a white or red oak is necessary (especially if you are going to make barrels). And sometimes identifying the individual species is needed.
Depending on the level of identification that is needed, it may only take a glance at the wood or it may take several hours and the use of a microscope. All most all trees produce wood cells that make it possible to distinguish their wood from the wood of another tree.
The related PDFs section on the right includes an extension pamphlet from the University of Tennessee which contains woods native to Tennessee, but many of them are found here in Mississippi.
There are also books from the U.S. Forest Service with information about the species of trees found in the United States along with a description of their wood.