Advice on getting started

So I want to get started with iPhone application development, I know what i'm going to want to create but I have no idea how to use the SDK. Essentially i'm going to be wanting to use Google Maps to show with the little red pushpins where to go for plane spotting. So I know what I want to do but I have absolutely no idea how to create an application.

So does anyone have any suggestions on how to learn these things or where to get help?