Steve Blank's "Four Steps to the Epiphany" is worth checking out.
Steve Blank is a super-experienced Silicon Valley technology entrepreneur who is best known for starting E.piphany, a successful software company, and also founded or worked at a broad range of meaningful tech companies over the last 30 years including Zilog, Convergent, MIPS, Ardent (one of the most innovative mini-supercomputer companies of the late 80's), and Rocket Science Games. Today he is a director at several tech companies including Immersion, Cafepress, Macrovision (boo hiss), and IMVU, and lectures on entrepreneurship at Stanford and UC Berkeley.
In other words, this is a dude with serious street cred.
And he's just written and published a book, The Four Steps to the Epiphany, that is a very practical how-to manual for startups.
In a nutshell, Steve proposes that companies need a Customer Development process that complements their Product Development Process. And he lays out exactly what he thinks that Customer Development process should be. This goes directly to the theory of Product/Market Fit that I have discussed on this blog before -- in this book, Steve provides a roadmap for how to get to Product/Market Fit.
Buy it, read it, keep it under your pillow and absorb it via osmosis.
Read more at Marc Andreessen's blog.