I assume you are pretty comfortable using pencil and paper? They are very cheap and easy to use, don't feel pressured into doing digital art just because it seems like everyone else is!
As for digital, I would also recommend that you invest in a tablet. If you are not sure if you want to pursue art seriously, then I think the medium or large sized entry level Wacom Intuos (formerly known as the Bamboo) is best, so you can see if digital art is right for you without burning a big hole in your wallet. But if you are already sure you want to paint like the masters in Photoshop and SAI, definitely skip the Intuos and go straight to Intuos Pro (formerly known as just Intuos), if you can afford it. The extra pressure levels, touch controlled shortcuts, and different mediums' nibs are worth the extra money, and if you play your cards right it will become a money making tool for you. If you're really rich, you could also just get a Cintiq, lol!
Either way, skip the small Intuos for drawing art, unless you're really strapped for cash and want to start ASAP. They're still a whole lot better than a mouse. Take this from an artist who is constantly hitting the limits on my small Bamboo/not-pro Intuos, the drawing area is a lot tinier than the tablet itself and drawing good lineart into the computer is almost impossible.
For programs, most people I know use Photoshop and SAI for painting. SAI is relatively cheap, only about $85 for a perpetual license with all rights to artwork, and very very powerful, so drop some $$$ on that if you can. To make FiM show-accurate drawings, SAI can work, but Adobe Illustrator and Flash are better (both are expensive though). If you need to stay free, the GIMP and Inkscape are great for raster paintings and vector work like the show, respectively.
If you are a high school or college student, look into getting Adobe products at a deep discount, like 75% off.