Hello,
Sunspots are made of the same plasma found everywhere in the Sun. The reason why sunspots appear to be dark is that they are much cooler in temperature than the surrounding areas on the Sun.
I'm not sure what you mean when you say that the surface of the Sun looks like it is being "sucked in" in sunspot photos. I think you might be referring to what scientists call granules. The granules are actually the tops of convection cells on the Sun where hot plasma is rising to the surface. This hot plasma then cools when it gets to the surface and sinks back down to be heated again. It is sort of like what happens when you bring a pot of water to a rolling boil on your stove. Convection currents can happen in any fluid, and may also be important to our weather here on Earth.
You can see a picture of granules here
http://en.wikipedia.org/w..._%28solar_physics%29
and an illustration of convection cells here
http://en.wikipedia.org/wiki/B%C3%A9nard_cells
and some experiments to try with a teacher here
http://www.esrl.noaa.gov/...ction%20Currents.pdf
Kris