Nice tutorials, stanford course and other resources

Here is a great resource for tutorials on iPhone development:
http://www.iphonesdkarticles.com/
The tutorials are well written and explained. I had found this website immensely helpful as I started out!

Another great resource for learning is Stanford's course on iPhone programming. Their latest lecture slides / videos available for free on Stanford's iTunes and course websites:
http://itunes.stanford.edu/
http://www.stanford.edu/class/cs193p/cgi-bin/drupal/

Also, I like the following books:
iPhone-Programmers-App-Driven-Approach-Developer
iPhone-SDK-Programming-Advanced-Development

The videos and books are the best resources if you want to learn all the aspects. Tutorials and online help can be used for specific topics. On a side note, I would suggest learning the apps in code rather than interface builder. Interface Builder is great however, it can be very confusing in the beginning as it hides certain information. Code is clear and transparent, so easy to begin with.