The series is set in New Gotham City, several years after it has been apparently abandoned by Batman. In his absence, Huntress, Oracle and Dinah are now the protectors of New Gotham: the Birds of Prey, and had taken over his war on crime. They are joined by Alfred Pennyworth, who serves Helena as she is heir to the Wayne estate; and Detective Jesse Reese, a police officer confronted with crimes and abilities he cannot explain.
A central feature of the series is the concept of metahumans: individuals born with powers that cannot be explained. No two metahumans have the same abilities (unless hereditary), and there exists a whole subculture of metahuman society that the outside world knows nothing about.
A lot of shows recycle, if anyone watches The Rookie, you see the same houses, the same sets in almost every episode. Unfortunately Birds of Prey recycled too, only they seemed to recycle plots. Like in cartoon, each episode was kind of a stand alone and didn't seem to lead anywhere, it didn't seem to move us to a more over-arching plot.
Which is kind of a shame, given that Birds of Prey was an exceptional comic in the 80s... but in the 80s the stories actually went somewhere.
And then the other problem was , well, it got WB, and in this era CW too fast and quickly, insanely quickly lost the focus and quickly resorted to Daswon's Creek with superheros... you know, it turned into Smallville, only with a darker and grittier background that didn't exactly fit the stories they fell back on telling halfway through the first season.
It was one of those shows that you got really excited about, but then realized what network it was on.