Wired recently put out THIS great graphic that illustrates in a layman-friendly way a lot of facts about the most interesting known exoplanets. Relatively sizes, distances, and temperatures, plus a quick primer on how exoplanets are discovered.
Exoplanets is one of the most exciting fields of astronomical study, and the one that may have the most long-range benefits. In terms of not only possibly finding other Earth-like worlds and alien life, but in more fully understanding the genesis and development of our own solar system. Plus of course there's the possibility, many centuries from now, our descendants may be visiting or perhaps even living on or around these far-off planets.
Anyway, check out the graphic!