Dependency Injection: Design patterns using Spring and Guice
By: Dhanji R. Prasanna
This one is available on Safari Proquest. Good intro to dependency injection / inversion of control by the guy who wrote the guice-servlet and guice-persist extensions, among other things.
Clean Code: A Handbook of Agile Software Craftsmanship
By: Robert C. Martin
Covers writing readable, self documenting code.
Refactoring: Improving the Design of Existing Code
By: Martin Fowler
Great book on executing evolutionary code change and design improvement while keeping code functional. Check out the author's website - he's behind lots of cool ideas in software engineering, there are some good articles there:
By: Douglas Crockford