Nightwing Primer:
Nightwing (1997) #1-70 by Chuck Dixon - Dick Grayson, having been the Superhero Nightwing for several years moves to Gotham's sister city of Bludhaven- Like Gotham only worse! - and sets out to solve crime as an independent hero while working as first a bartender and then a cop. Bit dated now but Dixon is a solid writer.
Nightwing #71-100 Continuing Nightwing's adventures in Bludhaven, this unpopular run by Devon Grayson introduced Nightwing's Romani history but also famously featured him being sexually assaulted.
Nightwing #101-106 - Dixon returns for a a flashback arc that deals with Bruce firing Dick, Dick becoming Nightwing and the arrival of Jason as Robin. Also featuring a random interlude with Deadman.
Nightwing #107 to #117 - Devin Grayson returns for a mob style story. This ends when Deathstroke drops a bomb on Bludhaven, destroying it.
Nightwing #118 - 124 Picks up one year later after Infinite Crisis. Dick moves to New York to find Jason Todd has been impersonating him. Has made lists of "worst comic arcs ever told" - probably deservedly so.
Nightwing #125-153 Rotating cast of writers including Wolfman and Tomasi. Lots of crossovers as Nightwing gets pulled closer and close to the centre of the Batverse.
Batman: Battle for the Cowl - Tony Daniel - Dick becomes Batman. Three issue mini, not well loved.
Batman & Robin by Grant Morrison: Dick and Damian are Batman & Robin. Their dynamic as a sort of reverse of the traditional Batman and Robin is established. Very popular but very Morrison-y
Batman The Black Mirror: Scott Snyder's Detective Comics run featuring Dick as Batman. Excellent.
New 52
Nightwing by Kyle Higgins - Dick is rebooted out of being Batman, though he had still been Batman. Moves to Chicago to Nightwing there. Wears a red costume. Average run, full of weird New-52 choices.
Grayson by Tom King and Tim Seeley - Dick's superhero identity is outed and he joins a spy ring as a mole for Batman. Often excellent.
REBIRTH
Nightwing by Tim Seeley - Dick becomes Nightwing once more and moves to a non-exploded Bludhaven on the advice of Pre-Flashpoint Superman. Classic Nightwing, safe and a little dull. Followed up by a fill in arc by Humphries
Benjamin Percy took over six issues ago. Batgirl features heavily, , but otherwise there hasn't been much to get excited over