Did you read "The passionate programmer - creating a remarkable career in software development"? I really loved that book, it contains a lot of practical tips and advice for how to improve your skills (among other things).

I read books on the commute to work (on the train) so this time feels less wasted. I especially liked: - Implementing lean software development - Implementing scrum - Domain Driven Desing - Head first rails - The leaders guide to radical management - Presentation zen

This is not only technical stuff, but I think the non-technical books are important too - they give you context and perspective.