Working with Linux day in-and-out can be challenging. There are some great descriptions of the tools available to do troubleshooting and analysis here. I found out new ways to use tools I'm already familiar with especially strace and lsof. Unfortunately it's more for a developer/coder type working with compiled code vs. the scripted languages (ruby, perl, python and php) so I wasn't able to get everything I'd hope for out of this book.