[ekianjo]

I'd recommend you read "Hacking the Xbox" by Andy Huang, it's a free ebook that explains a lot of the basics of hardware hacking and reverse-engineering, and then goes on to demonstrate what he did on the Xbox. Very insightful and fascinating read.

http://hackingthexbox.com/

[StavrosK]

Not any more, it seems? Apparently you can only get it as a physical book now? I'm not entirely sure, the text is confusing.

[ericfrederich]

I second this recommendation. Excellent book.