Shaley,
How handy are you with a skill saw, hammer, and do you have any friends that can help you lift framing walls?
I had a local company come in (pre-tractor days), level an area, compact the sand, and pour a "floating" slab. I had them space anchors for the base plates, 16" on center. When the cement was cured, my wife and I built there rest of the shed (10'x12' footprint with 12/12 pitch roof (I live in VT and get significant snow load). I built my own rafters (simple design) and did all the work except the standing seam roof. I only had to get one good sized friend in for 1 day to set the walls, strap up the rafters, then sheet the roof while squaring up the rafters. The doors actually took more time than anything else. I'll try to find a pic.
Note, sideing is T1-11. Not my favorite choice but within the budget when built. The shed is now 4 yr.'s old and with all that "extra room", it was filled to the brim the 1st year /forums/images/graemlins/frown.gif.
Tom
Tom