Remove the floor trim from around the edges of the floor with a hammer and pry bar. Don't break it as you take it off. Set it aside.
Lay plastic underlayment over the edge of the room where you want to start the flooring (usually the longest unobstructed wall). Cut the underlayment to size with a utility knife.
Lay the starting course of flooring next to the wall, snapping the planks together end to end and setting shims between the boards and the wall to make a thin gap there. Cut the final board in the course with a miter saw, as needed.
Lay the next course alongside the first one, connecting the boards by their sides. Arrange the planks so the ends don't line up between the two courses. Cut the last piece as needed.
Repeat and continue, laying each course alongside the previous one, making sure the ends of the boards don't line up, and working across the room. Lay out more plastic underlayment as needed.
Cut the last course of boards on a table saw, along their lengths, to leave ¼ inch of space between the boards and the wall.
Use your finish nails and hammer to reinstall the floor trim. It should hide the spaces around the perimeter.