About 18 seconds into this video. I've done this a whole lot. Their special blade isn't absolutely necessary, but they're nice. Where you're not working against concrete, a piece of metal flashing (duct tape the edges and use gloves) will prevent excessive scarring of the board you're working against by the tip of the blade. I would also suggest marking the boards with the nail ends in them some way so that someone doesn't try to cut them with a saw not knowing that they're in there. Wouldn't want someone to get hurt trying to re-saw them.
May you build something beautiful out of those boards ... man am I jealous!