Developing something needs lots of energy and information. Even though you are familiar with iPhone development, you might need some help for the area you are not familiar with but just got a new project you need to finish on time.
Following web sites can be helpful to get an answer for your problems.
http://developer.apple.com/ : Very first and principle site for iPhone documents.
http://lists.apple.com/mailman/listinfo/cocoa-dev : Mailing list for various topics in Mac OS X or iPhone/iPad/iPod
http://devforums.apple.com/ : You can find various topics about iPhone/Max software development.
http://www.iphonedevsdk.com : You can find wide variety knowledge from around the globe.
http://discussions.apple.com/category.jspa?categoryID=164 : Software developer forum for Mac and iPhone software
http://discussions.apple.com/category.jspa?categoryID=201 : Forum for iPhone
http://www.cocoadevcentral.com : You can find very huge amount of other useful websites and tutorial links.
http://cocoaheads.org : They do a regular off-line meeting to discuss about Cocoa
http://nscodernight.com : Similar to Cocoa Heads, but don’t have off-line meeting.
http://cocoablogs.com : You can find some useful Cocoa programming blog links.
http://www.iphonesdkarticles.com : You can find iPhone SDK tutorial
http://stackoverflow.com : Community site for programmers. You can find some very talented iPhone developer.
http://theocacao.com : Blog of Scott Stevenson who is an excellent Cocoa programmer.
http://www.wilshipley.com/blog : Wil Shipley is one of most experienced programmer in Objective-C.
http://rentzch.com : Very experienced programmer not just in Cocoa, but in every area.
http://eschatologist.net/blog : Chris Hanson is working in Xcode team. You can find some useful insight about Xcode.
http://cocoacast.com : Writes various topics about Cocoa programming.
http://iphonedevelopment.blogspot.com : You can find some information about ‘OpenGL ES’. He is an author of ‘Beginning iPhone 3 Development’.