Ray Wenderlich is a really nice guy and a good instructor. His site RayWenderlich.com offers a huge number of tutorials suitable for new and experienced iOS developers, written by his in-house team of experts. (Update: Ray just wrote me and asked me to emphasize that, so I bolded it.)
Now, he's releasing a self-published e-book called iOS 6 by Tutorials. A 1500-plus-page PDF, this book compiles all those tutorials into a single reference.
At $54, it's not exactly cheap, but if you already love the tutorials on his site, this reference is worth the price compared to the work you'd have to put in to figuring it all out yourself. The full source code is included.