Inflate and Inspect.
Infllating only takes a minute or two, don't skip a quick inspection before you allow the kids in.
Some units have two blower tubes on them. On one that will not have the blower attached to it, you will need to close the oppening. Pleat or fold the vinyl fabric as tight as you can, the use the attached strap to secure it shut. This doesn't have to be airtight-expect some air to leak out of this tube. Escaping air is what make your unit bouncy.
Hook the blower up to the other tube. Slide the blower opening into the tube, then pleat and fold the extra fabric around.
Normally, each inflatable runs off a regular 110 volt outlet on a 15 AMP circuit. This is usually what you would consider a "normal plug" in most homes and businesses.