iPhone developer's Journey

http://www.mobileorchard.com/14-essential-xcode-tips-tricks-and-resources-for-iphone-devs/
MobileOrchard is a pretty good website with lot of stuff for developpers. They've also got lot of tutorials which can be very useful at time. One of the best I've seen so far. This link brings you to a particular article taht can be useful if you want to begin developping.They resume their website like this :"Mobile Orchard is a weblog and podcast keeping iPhone and iPod Touch developers informed with news, interviews, links, and tutorials."

http://iphone.sys-con.com/

Ian Thain is the editor of this complete website. News, Tutos and many Infos about programming are on it. A great site to keep you up-to-date. Make sure to give it a look.

http://www.24100.net/category/apple/

Good site with a lot of news and a great iPhone section.

http://developer.apple.com/documentation/Cocoa/Conceptual/ObjectiveC/Introduction/introObjectiveC.html
 
For those who wanna get real serious about it, i suggest reading the basics of Objective-C written by Apple. Well done and (relatively) easy  to understand.

www.ipodtouchisapro.com

Great site. No more to say...No really the website is pretty cool but it's not very useful for programmers. Anyway plenty of stuff to learn and a lot of videos to make it easier. The dude, called itiap, will personnally answer your question if you have any. I personnally learned a lot form this website in my beginning. But don't be suprised, it's in french (even if he can answer your english questions) and there's a lot of jailbreak stuff. Great site overall.