Batman is a fictional character created by the artist Bob Kane and writer Bill Finger. A comic book superhero, Batman first appeared in Detective Comics #27 in May 1939, and since then has appeared in many of DC Comics’ publications. Originally referred to as "the Bat-Man" and still referred to at times as "the Batman", he is additionally known as "The Caped Crusader", "The Dark Knight", and "The World's Greatest Detective".
These 4 stories cover the origins and backstory of 4 important Batman opponents: Pamela Isley (Poison Ivy), Jonathan Crane (Scarecrow), Edward Nigma (Riddler), and Kirk Langstrom (Man-Bat). An interesting group of stories.
I'd like to point out that there is more than just Batman in this reading order. I've also included all the important story arcs from the DC Universe. You could almost consider this a Modern DC Chronological Reading order, centered on Batman.
One last note, there were a few stories that I wanted to read, but they weren't ACTUALLY part of the timeline (DC: The New Frontier, Vol. 1 for example)... so if I just picked a spot to include them. I'll make a note of any of these instances.
I've done alot of looking around, and used a combination of these sites to put this list together. Enjoy, any additional thoughts or pointers are welcome. This list will grow as I read through it myself.