To balance out the gushing of the fans here, I'll say the following.
It is, indeed, an exceptionally well done show from the perspective of watching the characters develop.
My advice to you as a novice to the series:
1.) IGNORE THE MYSTERIES. By the time you watch the finale, the mysteries will be irrelevant. This includes (a) who are the human/Cylon models, (b) what is the Cylon plan, (c) what's the deal with the prophecies and such.
2.) Remember: they made it up as they went along. Every detail was NOT planned in advance. Much of the show's major developments came not as a result of some overarching show bible, but rather as a result of the writers saying "Hey, wouldn't it be interesting if we did XYZ?"
3.) There is a VERY strong spiritual element to the show. This is NOT a hard sci-fi show, despite what the tone of the first season might suggest.
and finally,
4.) Do not expect major fleet vs. fleet fighter action. The first season plays very much as "life aboard an aircraft carrier." The show becomes less about that as it progresses, and becomes far more focused on the individual characters.
Probably Points 1 and 2 are the most important on that list. I only say this stuff so that you can manage your expectations to best enjoy the series. Personally, I felt the shift in focus (Point 4) hurt the show. I really disliked how the "mysteries" (Point 1) were handled and resolved, and I hated that the show seemed to suggest there was this overarching sense of where it was all going when the writers were actually just throwing it together on the fly and were themselves FAR more focused on the characters (Point 2). I can't stress that enough: this is a character drama. Do NOT be fooled by the plot points. They are merely there to provide interesting things for the characters to do. Do NOT be taken in by the intro to every episode which seems to suggest that there are bigger mysteries driving the show. The mysteries angle was, apparently, far more a product of the network than the writers, and the writers CLEARLY rebelled against that.
If you manage your expectations, and take the show is the writers seemed to intend it (IE: character drama, not "great big mystery plus lots of action" as the network tried to pitch it to the public), you'll probably really enjoy it. I think there's a lot to love, but as I watched it while it was going on, I ended up really irritated by how the show changed over time and how the network happily manipulated viewers when the writers had no intention of paying off the mysteries that were built up (or at least had no intention of paying them off WELL).