There are several apps, including Apple's Keynote app that will import and play Power Points. Hold in mind that importing to another app can lose some of your formatting and features. However basic Power Points should import with minimal problems.
On the playing side, there are several solutions. A combination of an Apple TV and a couple of cables (VGA and HDMI) should cover almost all possible combinations of equipment and wi-fi availability.
That is about all I know, since I don't do this myself. But the answer is, yes it is possible, and it is being done by business and educational people all the time. The details, well, you'll probably want to do a bit more research.
A search (using the Custom Google Search at the top of the website) or just in Google itself should give you a multitude of how-I-did-it articles about using the iPad for presentations.