So what's Birds of Prey all about anyway? The 'birds' are Dinah Lance, a.k.a. Black Canary and the wheelchair-bound Barbara Gordon a.k.a. Oracle (formally Batgirl) from the Batbooks and JLA. The two women have a unique relationship - without knowing who Oracle is, Canary 'teams' with Barbara long distance via satellite uplinks and video comm channels, guiding her through adventures ranging from rescues to information-gathering to out and out seek and destroy operations. The missions give Canary a chance to stay in the superhero game, while giving Oracle, who has a heavy load with Gotham, the opportunity to make sure her vision extends well beyond Gotham.
"It's the very nature of the way she's committed herself to fight crime. The entire world comes to her over a T-3 line. And, with the help of her operatives, she can do something about the injustices she sees. The irony of it, and the irony of the whole information age, is that sometimes she acts on incorrect data and that causes complications in what she sees as a clear-cut crusade for What's Right."
Part of the books' strong appeal comes from just that - as the sidelined coach, Barbara can sometimes screw up, leaving Canary vulnerable, or in a position to make a decision without the full information she's used to getting.