Hey folks I see you started a primer here for New Who Fans.
I got a linky for ya.
That thread is a summary done by one of the posters over at RPG.net and it is a rather detailed summary of every Dr Who series from 1963 to present. The summary is up to the books between the 7th and 8th doctor but hasn't made it to the TV movie yet.
An other excellent site is the Doctor Who Reference Guide which has, for me, become the one-stop for plot references.
This site has detailed (and I mean scene by scene) synopses of not only every televised story, but also all but a few of the audio productions, comic strips, original novels, and other odds and ends including spin-off productions ranging from independent films featuring Doctor Who characters to literary spinoffs like the Benny Summerfield novels. I can't recommend this site highly enough for people who are looking for detail on the Doctor's adventures but who either are unable to obtain past episodes/audios/books or don't have the time to watch/read them.