Code Complete - Steve McConnell - ISBN 1-55615-484-4
Billed as "A practical handbook of software construction" this book can be easy dismissed by the fact it's published by Microsoft Press, and, well, what do Microsoft know about writing software? The problem is, of course, this book is very good. Practical tips, garnered from various software development projects, not just from within Microsoft, and put together in a easy to read, if somewhat dry style.
Chapters are well laid out and reasonably self contained, so it is easy to pick the areas which relate to your current problem. The book is not language or OS specific, and anyone who is having to make the uneasy transition from developer to project lead should grab a copy quickly.