If you want to focus only on the iPhone, you can skip the Python and Ruby sections in part 1, but add Objective-C and ARM assembler. In addition, read and understand all content on the iPhone wiki (http://www.theiphonewiki.com).
In short, forget that idea. But maybe you understand now that there are only a few people that have these skills. So don't trust anybody unknown having a "new" jailbreak or unlock.