If you ever find yourself trying to explain the gospel of Gallifrey to a Whogin ("Who virgin," of course) and trip over the many and varied wrinkles of continuity, the singular plurality of the Doctor himself, then this poster should be your handout of choice.
This poster-sized Dummies Guide to Doctor Who gives a handy primer on all things Whovian: the TARDIS, the Doctor's quirky physiology, his reliance on tools of a sonic nature, even his lack of a given name. The one pertinent bit this infographic overlooks is the Doctor's fondness for skipping across space and time with attractive young women. Seems an odd thing to leave out.
Click over here for an vastly larger version.
(via Laughing Squid)