On my '01 I30T, I noticed that when I'm using the turn signals, there is a light on the right side, or the left side that will illuminate, but does not blink.

However, I believe my lightbulb on the left side isn't working anymore, what kind of bulb is it, and where can I get one?

 

The bulb you are looking for is commonly called an 1156, it's the bayonet style single contact bulb also used in the reverse lights and rear turn signals, easily found at any auto parts store in different styles, colors, etc