I went on to Lowe's site and bought a shed kit, a 10 x 12 x 7 Gambrel-roofed shed. They send all the wood pre-cut, the nails, etc., too. I figure there's about a $500 premium paid for them to take care of the cutting. I need a flat place to set it, and didn't just want to put down a pad of landscaping rock, so I've started building a wooden base (all green treated/pressure treated). First, I placed down the 4x4 posts, and set them in concrete. They're about 0.5" off square, when measuring the one hypotenuse, but the other is almost dead-on balls accurate. I still have to set the 2x6 joists, and then the plywood flooring over them. I'm starting to think that I should have just paid a guy to put down a concrete pad back when I had my driveway replaced in July. Getting the posts to square was a much bigger task than I expected, and I was expecting easy. The shed kit comes on two weeks from today, so then we'll see how well I can follow instructions.
And yes, the posts are all in 3" from the 10'x12' dimensions to account for the width of the 2x6 joist wrapping. I thinked before I done.
How is the shed sided? Typically, you want the siding (and/or sheathing under it) to start lower than the outside edge of the floor decking to prevent water intrusion, even if it's treated. In other words, is their 10 x 12 dimension an outside-of-siding measurement?