Because there are some issues with watching this, here is the order.
Copying from the site in case it ever goes down, but this info came from here: http://thunderpeel2001.blogspot.com/2010/02/battlestar-galactica-viewing-order.html
It's probably more confusing here on trakt, so go to the above linked site for a better layout.
The MiniseriesNight 1Night 2
Season 11.01 331.02 Water1.03 Bastille Day1.04 Act of Contrition1.05 You Can't Go Home Again1.06 Litmus1.07 Six Degrees of Separation1.08 Flesh and Bone1.09 Tigh Me Up, Tigh Me Down1.10 The Hand of God1.11 Colonial Day1.12 Kobol's Last Gleaming, Part I1.13 Kobol's Last Gleaming, Part II
Season 22.01 Scattered2.02 Valley of Darkness2.03 Fragged2.04 Resistance2.05 The Farm2.06 Home, Part I2.07 Home, Part II2.08 Final Cut2.09 Flight of the Phoenix2.10 Pegasus (56 minute extended version)2.11 Resurrection Ship, Part I2.12 Resurrection Ship, Part II2.13 Epiphanies2.14 Black Market2.15 Scar2.16 Sacrifice2.17 The Captain's Hand
Razor (101 minute extended version - not the 81 minute broadcast version)
Important note: This was originally broadcast just before Season 4, but chronologically it fits here, telling more of the Pegasus's story. Some people argue it's better to watch after Season 3, as originally broadcast, but it makes most sense to watch it here.
The reason that the placement of Razor is a hotly contested issue among BSG fans is because of a bit of dialogue at the very end (in the last 10 minutes) which sets the tone for Season 4 (barely even a spoiler). Everything else in this TV movie is not a spoiler.
So why place it here, and not where it was originally broadcast, if there's any sort of issue? Because, chronologically, the story is set here, and by the time you reach the end of Season 3, the story of Pegasus will feel like ancient history. Indeed, that was the complaint echoed around the internet from fans after Razor originally aired -- it had nothing to do with what was going on in the story at that time.
As a result of this, most fans agree it's better to watch Razor here. In doing so, you'll appreciate the story more and it will have greater emotionally resonance. In short: I highly recommend that you follow my advice and watch it here.
There is one small caveat, however: In order to deal with the above dialogue issue, and so not to unintentionally alter the tone of Season 3, I have two, very specific instructions that I recommend that you follow for your absolute optimum enjoyment.
I will try not to spoil anything with these instructions, so pay attention. You need to press MUTE on your TV (and/or turn off any subtitles) in the following two moments. Both of these moments occur in the last 10 minutes of the story, so you can relax and enjoy the first 90 mins before you need to worry.
Press MUTE when:
and shortly afterwards:
That's it! That's all you have to worry about. Two very small moments, and even if you don't unmute it, it's not a huge spoiler, it just unintentionally alters the tone of Season 3 if you don't, so do try your best to follow my instructions.
2.18 Downloaded2.19 Lay Down Your Burdens, Part I2.20 Lay Down Your Burdens, Part II
The ResistanceA 10 episode web-based series bridging seasons 2 and 3. (25 mins.)
Season 33.01 Occupation3.02 Precipice3.03 Exodus, Part I3.04 Exodus, Part II3.05 Collaborators3.06 Torn3.07 A Measure of Salvation3.08 Hero3.09 Unfinished Business (70 minute extended version - Note: Not included on Region 2 DVDs, but is included on ALL Bluray releases.)3.10 The Passage3.11 The Eye of Jupiter3.12 Rapture3.13 Taking a Break From All Your Worries3.14 The Woman King3.15 A Day in the Life3.16 Dirty Hands3.17 Maelstrom3.18 The Son Also Rises3.19 Crossroads, Part I3.20 Crossroads, Part II
Razor: Yes, this again. (Well this is where Razor was originally broadcast, after all.) Remember the last 10 minutes where I told you to MUTE two small moments? Well, guess what, now is when you get to go back and hear what was said. Watch the last 10 minutes of Razor here.
Season 44.01 He That Believeth In Me4.02 Six of One4.03 The Ties That Bind4.04 Escape Velocity4.05 The Road Less Traveled4.06 Faith4.07 Guess What's Coming to Dinner?4.08 Sine Qua Non4.09 The Hub4.10 Revelations
Season 4 Continued (aka "Season 4.5" or "The Final Season")4.11 Sometimes a Great Notion
The Face of the EnemyA 10 episode web-based series (although it plays together like an intense mini-episode). (36 mins.)
4.12 A Disquiet Follows My Soul (53 minute extended version - only on Bluray releases)4.13 The Oath4.14 Blood on the Scales4.15 No Exit
The Plan (DVD/Bluray movie)A stand-alone movie that shows (approximately) the first two seasons from the Cylons' perspective. (You finally get to see "The Plan", mentioned all those times in the opening sequence!) Although The Plan was originally released after the show had finished, it is generally agreed that it should be watched here, so that everything is all tied up when you do reach the end.
4.16 Deadlock4.17 Someone to Watch Over Me4.18 Islanded In a Stream of Stars (62 minute extended version - only on BluRay releases and Region 1 DVDs)4.19 Daybreak (150 minute extended version - only on BluRay releases and Region 1 DVDs)
The Plan : This is where this DVD/Bluray movie was originally released (after the show had finished). It seems universally agreed that it's preferable to watch this after No Exit, instead of after you've finished the entire series, but there's no harm in waiting until now.
Then Caprica the series: http://trakt.tv/show/caprica