If anyone could explain where to start with the collection. I know that they are probably set up in a certain order but I see a lot of different numbered issues with different writers so I’m very confused. Also it seems like they have some filler issues that could be skipped but I’m not 100% sure on that.
Knightfall (which is actually three arcs: Knightfall, Knightquest, and Knightsend - there’s not really a collective title, so the first arc’s name gets used as a shorthand for the whole story) is a little complicated since it ran through seven different titles and a two miniseries over the course of a year or so. My advice is to look up a reading order (DC Comics Database has one that I used, which seemed to be accurate). Filler-wise, much of the Knightquest part of the story is not all that important and frankly not as good as Knightfall or Knightsend, but it’ll be a little hard to keep track of what’s going on if you don’t read it. There are also a few interim issues of Robin and Catwoman that aren’t technically part of the story but lead into issues that are, so any time you come to an issue from one of those series, it’s probably worth reading it through to that point if you really want to be thorough. Probably the best way of avoiding filler is just to skip anything written by Alan Grant.
Though if you just want to see Bane break Batman’s back, none of that really matters because Knightfall (which is the one where that actually happens) is probably the simplest of the three arcs. It just bounces between Batman and Detective Comics for the most part. You may want to read Batman: Sword of Azrael and Batman: Vengeance of Bane before you get started, but you can get the general idea without them.
You can use the search functionality on DCU. Search for Knightfall. Under News, you can find an article about Knightfall being included with DCU. It has links to the three Knightfall collections.
Here are the links: