First go through this[1] for a quick intro to Objective-C:

Then again, just checkout hw1[2] in Stanford - HelloWorld to iPhone SDK. This is the best hand-holding intro to Obj-c. If that doesn't suffice checkout the earlier class videos.

[1]http://courses.csail.mit.edu/iphonedev/ [2]http://www.stanford.edu/class/cs193p/cgi-bin/drupal/