In fact, many people I know/interview have very fundamental gaps in their knowledge and in most cases I discover that it is partly due to the fact that they never spend time learning things from books.
...
A decent technical book would provide a learning framework and good coverage on the topic it discusses.
...
How much time do developers often spend researching on the internet about a particular Java or .NET topic, like generics or reflection, during the course of developing a software? If they learn it end-to-end from a decent book, the researching time would be much shortened as the author already did that for them.
...
Reading a lot of books does not guarantee good developers, but not reading any book at all (not including university’ required readings) does guarantee bad developers. So, next time when you learn just about anything new, be it a programming language, tool, development process, or technology, ask your most knowledgeable colleagues for their recommendations, check out the blogsphere as to which books people often mention about, review Amazon’s rating, and pick some decent book(s) to learn. It is a good investment
http://www.buunguyen.net/blog/when-you-learn-new-things-learn-from-books.html