My buddy Eric Grubbs has written a book from the inside about some of my favorite bands called Post: An Anthology of American Post-Hardcore /Whatever-You-Call-It-Core: 1985-2005. I just ordered it so I can't tell you how great it is, but I can tell you he worked for many years and really hard interviewing the bands in the book and really cares about the subject.
Back in 2005 he came and stayed at my place in Austin in order to go to SXSW and talk to some folks in his book that covers some of the best Post Hardcore (Usually called Emocore or Emo) bands that existed back when I was in school. It even includes the precursor to my all time favorite Hey Mercedes, Braid. So if you want to learn more about Jimmy Eat World, At the Drive In, Promise Ring, Sunny Day Real Estate and others...I encourage you to check it out.