App Architecture and Design (iOS Apps)

I LOVE the RW tutorials.

I was also wondering if anybody here could recommend some good architecture and design pattern sources. I’ve been able to wing it but would love some blueprints, best practices, and input from others.

For example, lets say my app idea requires some central server and DB. What are the various architectural options to do that? Pros and cons? What are the different ways my app can interface with the server? Pros and cons? etc.

Also, app specific stuff like how folks architect their apps? How does that architecture effect the responsibilities of classes?