If you haven't seen the television series Babylon 5, I envy you. Not because it's no good; on the contrary, I consider Babylon 5 to be The Lord of the Rings of science fiction for television, and that's saying a lot. I envy you because, though I just finished watching episode two of season three, I've seen it before, whereas you have the opportunity to see it for the first time. Babylon 5 really is that good, if you give it the chance. If you're willing to follow my advice, and you're ready to watch some Babylon 5, I've got some guidance for you.
First, get a hold of the pilot episode, The Gathering, on DVD. Now watch it. Be forgiving; the series gets much, much better than this. (Be sure *not* to watch In the Beginning, which is on the same two-sided DVD; it may seem like the right thing to do, but it's full of spoilers for the first four seasons, so you'll want to exercise self-control and not watch it until you're done with the fourth season!)
Once you've watched The Gathering, head over to The Lurker's Guide to Babylon 5 and read the appropriate guide page. There's lots of great stuff there, all written when the pilot first aired, with few, if any, spoilers for the rest of the series. The guide pages are key to getting the full Babylon 5 experience.
Next, get a hold of season one, watch the first episode, and check out the guide page. Continue watching episodes and reading guide pages until you're done with the first season. Don't watch more than one episode per day; Babylon 5 needs to be savored, and there's plenty to think about. Don't watch any of the special features of the DVD -- not even the introduction -- as they'll almost certainly contain spoilers, and you'll want to be just as floored as I was as the series arc progresses.
When you're done with season one, continue on to season two. Then season three. Then season four (which isn't quite released on DVD yet). Now feel free to watch In the Beginning. Great stuff! Finally, watch season five, which probably isn't as good as the first four, but was still a fun end to the series. Now that you've seen all there is to see, feel free to check out the special features of the DVD sets. By this time, they might have released a few of the other Babylon 5 movies, or even the short-lived Babylon 5 spinoff series, Crusade.
If you're like I was, you'll still want more Babylon 5, so you'll want to read some of the great Babylon 5 books. The best books fill in many of the stories in between the stories. The Psi Corps series (1 2 3), the Legions of Fire series (1 2 3), the Passing of the Technomages series (1 2 3 0); all great stuff. I'm currently reading To Dream in the City of Sorrows, another great book that fills in some of the details after season one.
Perhaps I sound like a bit of a fanatic, but I've really enjoyed Babylon 5. I hope your experience is as good as mine!