This is my recommendation as well. From the basics of Objective-C (for people already familliar with object oriented programming) to best practices, design patterns and individual components. No other single resource has given me a stronger grasp of all the important concepts of the platform, and I'm still amazed that it's available for free.
Starting Tuesday, (when my first Macbook arrives!) I will be going through this course and posting my daily results and thoughts on my blog, which I will also set up on Tuesday.
I currently am slightly comfortable with Python, I have gone through some C tutorials, and I will keep going through OOP tutorials until Tuesday.
I plan on spending 10+ hours a day on this until I finish the course and feel comfortable enough to create my first app, which will be the next step.