John, you will not have a problem getting plans and info. Your problem will be getting through all that's out there.
Rubbermade has sheds. I know a lot of shops that use smaller ones for their loud equipment that they run slightly away from the main building. They have been happy with them.
There are MANY plans that have appeared in home improvement magazines and books. You library probably has many of the books. I'm sure that there are plenty of web sites with plans. As you start looking, you will probably be so swamped with ideas that will make a decision tough, so let me make a suggestion. Sit down with a sheet of paper and write down design requirements. Try to list these in order. Then go to reality time.
You will not be able to have a full, professional quality concrete floor and have much money left for the shed. A wood shingle roof may look great and match your house, but a shed under the roof might be nice. Do you have a problem using pressure treated wood? These are the kind of things you should consider. When you have these resolved, THEN it's time to look at plans.