A bit late................. but thank you fellas :o)))))
Needy, I assume this is "click together" if you know what I mean.
I can't understand why they say that. The product I usually use (Howdens) says quite the opposite. So do others I've seen. The idea is that a continuous line is like a "perp" in bricklaying. A perpendicular line where all the vertical joints line up, making it all very weak.
Same for flooring. The joint is the weakest point, so you need to stagger them.
Mex is right. Start against one wall... continue until you get to the other wall and cut the last board accordingly.
Take the offcut and set the cut edge against the first wall and continue with the next run.