There are a lot of videos out there on building a raised bed garden using recycled materials.
This isn't one of those.
I cheated and actually purchased a kit which included everything I needed to put together 3 beds of staggering heights. I could have put it together in an "L" shape, but choose to place it all in a long run. This just fits the area of my lawn that gets enough sun, better.
Greenes Cedar Raised Garden Kits - North American Cedar made in the USA
This video shows the process to stack and expand Greenes Cedar Raised Garden kits. It's the clean version without the swearing involved in my own reconfiguration!