37 signals has released their book, "Getting Real" for free. The pdf still costs $19, but you can read it online for free. I would highly recommend this read to just about anyone that works on web apps, it may change the way you think about the web application development processes. Heres an excerpt about the book from the 37 Signals website:
Want to build a successful web app? Then it's time to Get Real. Getting Real is a smaller, faster, better way to build software.
- Getting Real is about skipping all the stuff that represents real (charts, graphs, boxes, arrows, schematics, wireframes, etc.) and actually building the real thing.
- Getting real is less. Less mass, less software, less features, less paperwork, less of everything that's not essential (and most of what you think is essential actually isn't).
- Getting Real is staying small and being agile.
- Getting Real starts with the interface, the real screens that people are going to use. It begins with what the customer actually experiences and builds backwards from there. This lets you get the interface right before you get the software wrong.
- Getting Real is about iterations and lowering the cost of change. Getting Real is all about launching, tweaking, and constantly improving which makes it a perfect approach for web-based software.
- Getting Real delivers just what customers need and eliminates anything they don't.