Matt Neuburg, who writes the Script Debugger documentation, has kindly provided a PDF version of Script Debugger 5.0’s On-Line help.
Script Debugger 5.0 Help Book (PDF, 4.1MB)
Matt Neuburg is the author of AppleScript: The Definitive Guide, 2nd Edition, and more recently Programming iOS 5: Fundamentals of iPhone, iPad, and iPod touch Development.