It's the longest-running science fiction show on television, but for new fans, how easy is it to start watching the BBC's Doctor Who? After a great Christmas special, we've decided that it's time to tell you all you need to know.

What You Need To Know (1):

Doctor Who is a long-running British TV show that started in 1963, before running continuously through 1989, being revived for an unsuccessful TV pilot in 1996, and then successfully revived in 2005 for a run that's continuing today. It was originally intended as an educational show aimed at children - a function of the Saturday afternoon timeslot it was created for - but soon gained a multi-generational audience that appreciated the off-kilter mix of science fiction, comedy and pantomime the show happily provided, keeping it alive for twenty-six years until it was unofficially cancelled - officially, "suspended" - due to falling ratings.

(One reason that the show lasted so long in its original incarnation was the inventive way of replacing the lead actor in story: Lead character The Doctor was given a background in which, instead of being killed, he would "regenerate" into another actor. Initially, the character was given twelve incarnations, but now that we're already on the eleventh, that's been retconned into many, many more.)

After a failed attempt to revive the series for American television in 1996, Doctor Who returned to television screens in 2005 after years of development, headed by critically-acclaimed British drama writer Russell T. Davies - Creator of the original British version of the drama Queer As Folk - and was a surprise success. Davies helmed the series through to the end of 2009, with the series continuing to grow in popularity with every season. The revived show was enough of a hit to launch two spin-offs, the more adult-based Torchwood, and the all-ages Sarah Jane Adventures, both overseen by Davies. Current showrunner Steven Moffat took over Doctor Who with the fifth season of the revived series in 2010.

What You Need To Know (2):

Doctor Who is a series about a time-travelling alien called the Doctor (Not, importantly, "Doctor Who"; that phrase is generally one heard in response to his introducing himself as "The Doctor," if at all). Although he likes to skip around the universe in his time machine - the TARDIS, which stands for Time And Relative Dimensions In Space - he tends to return to Earth and/or humanity for reasons that seem to boil down to "He's fond of us." Fond enough to keep inviting humans to join him on his adventures which, more often than not, involve saving the day (if not the universe) from any number of nefarious plans thought up by evil forces, aliens or cosmic entities beyond our mortal comprehension.

Unlike most science fiction heroes, the Doctor has two very specific qualities: He's an optimist, and he's a pacifist. He'd much rather think - or, more likely, talk - his way out of trouble than shoot something, and he really, really wants everyone to get a happy ending wherever possible.

Why Should You Watch?

Because, at its best, Doctor Who is a smartly-written, well-acted science fiction show that isn't afraid to be funny and scary and anything else that'll make the show entertaining. There's a formula to the series, yes, but it's a remarkably adaptable one that will happily do whatever it takes to please (At its worst, it can be pretty embarrassing, but never "Spock's Brain"-level unwatchable).

The Show's Been Running Since 1963?!?

Yes. And, interestingly, everything that's happened since then "counts" - Although it's never been explicitly stated, the revival of the series in 2005 seems to follow on from the continuity of the 1963-1989 series and 1996 failed pilot, with on-screen cameos from former Doctors on more than one occasion. Don't worry, though; this isn't a heavily continuitied series, with each season - and, indeed, each episode - pretty easy to understand for new viewers. Additionally, each new Doctor generally brings around a reboot of sorts, making it very easy to start over with.

Where Should You Start, Then?

Honestly, the show's 2010 season - the first for new Doctor Matt Smith and new showrunner Steven Moffat - may be the best the show's ever been, if you ask me. The first episode, "The Eleventh Hour," is probably a great place to start; if you don't like it, chances are the show isn't for you (Although there are, I think, better episodes in the season). If you dig that season, jump back and watch everything from the 2005 revival onwards, but be warned: The longer Russell T. Davies is in charge, the more over-the-top and sentimental the show becomes. But there's some great stuff in those four seasons, including episodes written by Action Comics and Batman and Robin writer Paul Cornell. If you become entirely addicted, there's always the twenty-six seasons from the original run, but be warned: They are an entirely different beast altogether, with good writing but significantly lesser special effects and, in many cases, acting.

And How Should You Start?

The show is available on iTunes and DVD, as well as pretty extensively rerun on BBC America.

Most Importantly, Should You Start?

Definitely. I may be slightly biased by nostalgic love - this is a show I grew up with - but Doctor Who is one of the best science fiction television shows ever made, and right now, it's better than its ever been. Not even giving it a try is being stubborn to the point of stupidity.