I love the powershot series. As someone who got used to using her dad's Nikon before leaving home, I love having the freedom of being able to choose the Aperature or Time priority settings. A DSLR is just not in the cards for me right now, so the Powershot is a good alternative. Also, it has a "macro" setting, which allows me to photograph things close up -- key when I want to get up close and personal.
My recommendations are to play around with the "scenes" options and get a library book about photography (a children's or young adult book would be a perfect starter, as it would just explain the basics) to learn about aperature and time and light and how it affects your photos.
Most importantly, do as Phil suggests and PRACTICE! (and don't use the digital zoom - just use optical zoom.)