Well I finally started my 5x10 this weekend. I'm using the generic Benroy plan from this website and modifying it to 10'. I ordered the 1500 lb. landscaper trailer from Harbor Freight on Friday. As I said in my "Plywood Blues" post I have glued the 1/2 outer and 1/4 inner birch panels offset 2' on each end to make a 10' wall since I couldn't find 3/4 4x10 birch plywood. I assembled my floor this weekend and applied the black roofing goop to the underside. Fortunately I have a workshop with a dehumidifier as it is raining today and it looks like the black goop will take some time to dry. I have more gluing for the walls and should be able to layout and cut the walls later this week. Then I'm kinda stuck till my trailer arrives.
I appreciate the encouragement of everyone on this website. I'm sure I will test your patience as this project continues as I tend to overthink things sometimes. I've taken some pictures and will start a build album soon.