The SNES is a classic system, with many good games. So... lets start at the beginning.
System- Smaller than a normal VCR, bigger than a Wii, it is a light gray color, with purple switches (Power, Reset) and a darker gray eject button. It has a red power light, 2 controller ports, and a cart slot on top, like the NES 2, SNES 2, or N64.
Controller- It has a D-pad, A, B, X, Y buttons, Start, Select, and two shoulder buttons (L and R). Advice- Don't get the crappy 3rd-party controllers. The buttons have a very nice, clean feel to them, and the cord is fairly long.
Graphics/Sound- The SNES has fair graphics, which, in many games, is a 2D view with a background. It has Sony sound chips (yeah, Sony and Nintendo weren't always enemies), which give it very good sound.
Games- Imagine NES games, with vastly improved graphics, and starting to go to 3D, and if you can't imagine that, then just imagine this: It has many good games, like Super Mario World and F-Zero, and some not-so-good ones, like NCAA Basketball.
Overall- The SNES is a great system, with many great games, and a good controller.