In the tags I frequent on Stack Overflow, a big chunk of questions should be answered with some basic knowledge about how to debug things - ie., teaching the OP to fish - instead of giving a fix for the piece of code presented.
Are there any good debugging tutorials for newbies, especially
Basic debugging techniques - understanding a piece of code, finding the problem by walking through it step by step instead of posting on SO and saying "it doesn't work"
How to debug simple PHP scripts (For situations like "my POST variables aren't showing", etc.)
How to debug Ajax scripts (How to use Firebug to see what gets sent, etc.)
but also other languages and platforms?