Carpentry and Woodworking - Multipurpose 'box'

Hi! I'd like to build a multipurpose 'box' on my back porch. The porch has a concrete floor, and the back of the box would be against a wooden wall. I'd like to build it so an open wheeled cart, which I'd also have to build, would slide in and out of one end--it would hold 3 bins, at least 50 lbs. each, of grain. I'd like the middle section to be lower-it would be a potting bench, with storage for gardening below it. The other end would be for storage for general use, built as high as the grain storage end. I have had no previous experience building anything. I know to measure everything out, and to draw basic plans from the measurements, and I can do that, but don't know much else. Where do I start? And don't say 'hiring someone who can build!':D

Thank you very much,
Mary

First start with some sketches of plan, basically you need to figure out your height, width, and depth. Include enough room for the cart and basic decisions like free-standing or attached to the house and how anchored to the porch. Get some grid paper and make a scale drawing so you know about how much lumber you'll need. Then you need to have a basic budget for lumber and materials. Once you have a scale drawing you need to decide on materials. What will walls, roofing and doorway be made of or any windows. Since it is outside you would probably consider treated pine or something like cedar or redwood or you may want a metal product. Types of products will effect your budget. Any requirements for electrical or plumbing? The easiest construction for me would be to frame it out like a house and cover it with some siding and a simple roof. Probably easier to get a basic framing book at the library than me trying to tell you. Once you have the basic frame up then work on the sections or the benches you want to install. If you have a local home improvement store look at some their prebuilt sheds for construction ideas. Minimum tools you'll need are hammer, saw, level, perhaps a drill. Hope this helps.

Hi,
Good advice from RS-Petty. Library is a good source, look for books of sheds and mini barns, lean to sheds, and the likes of. Lots of these books have the framing laid out in them, just alter it to your needs. Grain I would keep in plastic or metal containers so as to not draw any rodents or other animals. Also check your building codes before starting.
good luck,
Trent