I favor http://www.raywenderlich.com which has an incredible amount of information. Whenever I face an issue, I tend to find the answer somewhere there.
Another interesting solution is HTML5, since Apple doesn't require a developer license for your HTML5 apps to run on iPhone and iPad.
iTunes U, to which you get freely access when you get the Mac you will need for development, holds troves of video, from Apple and from Universities such as CalTech or the MIT, related to iPhone native development, as well as to HTML5-based development.
