These are all collected in Trade Paperback and Hardcover form-- so you can assemble a collection of not only the greatest Bat-stories ever put to paper, but the ones that make the character who he is:
BATMAN CHRONICLES #1 - Collecting the first ten appearances of the ferocious pulp avenging Bat Man of Detective Comics pre-Robin as well as Batman #1 (1940) this'll give you the basics.
BATMAN CHRONICLES #2 - Picking up where #1 leaves off-- this collects Detective Comics #39 - 45 and Batman #'s 2 and 3. Early appearances of The Joker and The Catwoman. Great early Batman stories.
BATMAN TALES OF THE DEMON collects some of the really great Batman stories of the 1970s as he faces his greatest Bronze age advesary, Ra's Ah Ghul! Great art by Neal Adams, Don Newton and Irv Novick in this collection.
LEGENDS OF THE DARK KNIGHT- Marshall Rogers is THE definitive Batman artist-- hands down. His run on Detective Comics as written by Steve Englehart is not only the GREATEST run ever on Batman it's the basis for Tim Burton's Batman film. If you can only get one collection this is it.
From there, you can go on to a number of collections including THE DARK KNIGHT series by Frank Miller, but what I've listed gives you what you need to know to get you the best of Batman up to the middle of his career.
