Yellow pine is an ideal wood to use because of its resistance to wood rot. Hardwoods such as oak and poplar do not hold up very well. White pine is often used because it is readily available, easy to work with and holds up adequately. Do not use pressure treated lumber. Do not paint or treat the house with wood preservative.
Position nestboxes out of the most intense sun and out of the reach of predators.
It is best to set the box on a pole with a baffle underneath to protect the nest from predators such as snakes, raccoons and cats. If fire ants are a problem, sprinkle an insecticide on the ground around the base of the pole. If a species different from the one intended should nest in the box, leave it alone. All species need help. Inspect the box periodically but be careful not to disturb the birds or eggs.