First, thank you everyone on the site for the excellent contributions, ideas, comments, and inspiration!
I decided to attempt this bed after I made the Clubhouse bed for my 2 yr old and his older brother was jealous beyond belief (to be expected, right?). My 4 yr old has a full size bed, so I needed a plan that was a little friendlier to changing the bedding and with a little more clearance underneath.
I came across this plan and knew it would be perfect. One of the previous comments included instructions for materials and cuts for a full. I followed those and like magic, this bed came together in a little over a week. My 4 yr old LOVES it and calls it his Castle Bed!
I especially like that the materials are pretty consistent - 2x4s and 2x6s.