If you want to make great pictures, then take my advice and install these programs...

Sai is probably the best art program I've ever seen. It's pretty easy to use and figure out, and has lots of brushes to add more texture to your art. You can adjust the settings of pretty much everything to end up with cool effects. Most of my recent digital drawings are done with this program- It's definitely recommended. Here's what the interface looks like;

It seems a bit confusing at first glance, but you get used to it easily. Above is a brief guide of the basic stuff in Sai.
​Cost: 99 AUD

Wacom is a great drawing tablet with awesome pressure sensitivity. It works very well with SAI. Problems can occasionally pop up with the pressure sensitivity, (at least with mine) but they're very easy to fix, and there are plenty of helpful tutorials online.
Cost: 168 AUD (professional) 114 AUD (regular)