Erm, it's just like any other Canon DSLR really. It's just much easier to use than the consumer grade bodies, and the image quality and high ISO noise performance is in another world. The thumb wheel on the back, bigger ISO range and much easier ability to change settings on the fly are all awesome.
All I'd say is go out and practice changing various settings on the fly, and get used to how the body feels in your hands. The ISO button is the nearest to the shutter button, and works off the click wheel at the top of the body. ISO is displayed in the viewfinder, which helps enormously.