Place the cedar trees on a work surface. Cut all of the limbs from the trees with branch cutters so that you are left with just the trunks.
Measure and mark two trees at 48 inches using a tape measure and lumber crayon. Measure and mark another tree every 24 inches to divide it up into four equal parts.
Cut the trees that you marked in Step 2 to the marked lengths using a bow saw. You should have four 48-inch lengths and four 24-inch lengths. This will leave you with two 96-inch trees.
Place the 48-inch and 24-inch lengths of tree on a work surface. Cut each end of the tree lengths using a drill equipped with the tenon cutter from the set. This will create a tenon or notched end that will fit into a mortise or notched hole.
Lay two 96-inch tree lengths on a work surface. Cut a mortise 4 inches in from each end of the two trees using a tape measure to ensure accurate measurements and a drill equipped with the mortise cutter from the set.
Place the two 96-inch tree lengths on the ground parallel to each other. Space the trees 24 inches apart. Connect the two tree lengths by inserting one 24-inch length into the mortises at each end. Insert the tenons on the ends of the 24-inch lengths into the mortises 4 inches in from the ends of the 96-inch tree lengths. You should now have the rectangular base assembly for the firewood rack.
Cut a mortise in each corner of the rectangular base assembly, 3 inches in from each end of the 96-inch tree lengths. Insert one end of the 48-inch lengths into those mortises so that they fit snugly. These are the vertical uprights for the firewood rack.
Make a mortise in the inside, top ends of the 48-inch uprights, 4 inches down from each top end. Insert one 24-inch length between the 48-inch uprights at each end and press the tenons and mortises snugly together.
Hammer two square head nails through each mortise and tenon joint to secure the firewood rack together.