In the mid 1980's DC decided to clear up fifty years of continuity in their universe by putting out a series called A Crisis On Infinite Earths. As someone who didn't know too much about DC characters and storylines when I initially read it, I found it a confusion of huge events involving too many characters. My opinion of that title has changed over the years, but I still think it would be a terrible place to start reading comic books.
What followed Crisis was the rebooting of several of DC's most popular characters. The most successful of these was Frank Miller and David Mazzucchelli's Batman: Year One.
The story opens with Lieutenant James Gordon moving to Gotham and joining their police force, while Bruce Wayne returns to Wayne Manor after twelve years abroad. And it follows the two as Gordon fights Gotham City Police Corruption, and Bruce Wayne dons the cowl for the first time. We also see a prostitute named Selina Kyle transform herself into Catwoman. And when the Gotham Police Department goes under investigation, District Attorney Harvey Dent is called on to the case.
If this storyline sounds a bit familiar, it's because Year One was one of the main sources for Christopher Nolan's Batman Begins. The story also involves The Falcone crime family's attempt to keep a tight grip on Gotham, mostly by controlling police commissioner Loeb (no relation to Jeph , as far as I can tell).
Mindy Newell and JJ Birch's Catwoman: Her Sister's Keeper is a companion piece to "Year One", which focuses on the Selina Kyle storyline. I recommend reading it just after Year One while the story is still fresh in your mind. There are a couple of scenes that appear in both books. And it's always interesting to see a scene drawn by two very different artists. Mazzucchelli employing a very comic-noir style while Birch's work looks like it would be at home in early Sandman comics.
It's also interesting to see how the two handle dialog. Miller has a "gritty" cop drama style with characters speaking with no flash or style. There's no sense of him trying to be witty, it reads like real people in a real situation. Newell, on the other hand, employs a lot of 80s snappy patter that, much like old paper, has yellowed a bit over the years. It's not bad writing, it just includes the occasional pop culture reference that is no longer in the vernacular. "You're a better nun than I am Gunga Din" is a "Where's The Beef" for movie nerds. It's still a solid story, and an important character study of Selina Kyle.
So this was the easy entry. Where to begin. How to become familiar with the early characters. We've established Bruce as the Batman, Selina as Catwoman, James Gordon as a flawed but well intentioned police officer, The Falcones as the family you least want to fuck with, and we've met Harvey Dent. We also have Gordon mentioning that there are more Falcones back in Chicago that he has a history with. And, as the story comes to a close, he stands on the roof, waiting for Batman, so he can tell him about a new criminal in Gotham; The Joker.
Batman Year One: Story 5/5, Art 5/5 with some back matter by Mazzucchelli.
Catwoman Her Sister's Keeper: Story 4/5, Art 3/5