Trim off the tongues from the boards that will edge the first wall. This is easy to do with a sharp utility knife, a table saw, circular saw. Trim the edges of the planks against the wall and start laying the first row on the longest wall. Start on the right side and work to the left.
Put a full-size plank against the wall, spacing it about ¼ to 3/8 inch away from the wall. Make sure the groove edge faces out. Place scrap wood spacers between the flooring and the wall to keep this gap. Continue with additional full-length planks and work toward the left to the end of the room.
While working, lock pieces to each other using a hammer and a tapping block to tighten the joints. The end joints should be tight, with no gaps. Manufacturers suggest tapping the planks with a rubber mallet to close the end joints.