I'm looking to broaden my horizons and develop some apps for the iPhone. I have 15 years of software development experience, starting with C++ and then transitioning to C#. Nearly all of my experience is developing for Microsoft platforms (Windows, ASP.NET, etc), with a brief stint doing some Java/Oracle stuff.
Does anyone have any suggestions on good tutorials that will help me come up to speed on XCode and the iPhone SDK? I don't really want a "this is a computer" level of introduction. I have written a couple of very simple iPhone apps that work, but I am still having a difficult time finding my way around in XCode and familiarizing myself with the SDK.
EDIT: Thanks for the responses. I should clarify that Objective-C isn't terribly confusing for me. A good walkthrough of XCode (especially Interface Builder), and a more thorough understanding of the relationship of the important classes in the iPhone SDK would do me wonders. I could also do with some "best practices" on structural layout of an iPhone application.