The plans are in my head. 8ft long, 4ft wide, 6ft tall, 9ft radius, (12) 2X4 stringers cut to 46.5inches(you should have a stringer every 10 inches from top to bottom), (4) 2X6 stringers cut to 46.5inches, for bracing the bottom back corner, top, and middle bottom. (1) 8ft 2X6 for angled brace on the back. 2 sheets of 3/4 inch plywood for the sides, and 3 sheets of 3/8 plywood for the decking. All the above materials can be purchased at home depot for between 50 and 65 dollars. I used deck screws to put it all together. Nails suck ass!

 hmmm... I know how to use tools, shop class might just might pay off...

 I layed the plywood on my drive way; Used a 12ft 2X4, screwed at one end into a crack in my driveway. Measured distance of radius from screw/pivot point; cut the 2X4 there and taped a pencil to the end. Its like a giant protractor.