Control the tractor around the map and start cutting trees. Each log is worth 50 dollars and you will have to reach a certain amount of sum of money on each level to be able to pass it. Only some of the trees on each map are marked as future timber. Once you get near a tree press the Z button and you'll trigger a tree cutting mini game at the end of which the marked tree will be cut and placed on the Lumberjackmobile.