If you know C/C++ and want to get into Objective-C I recommend the "Objective-C Guide for C++ Programmers": <a href="http://ktd.club.fr/programmation/fichiers/cpp-objc-en.pdf" rel="nofollow">http://ktd.club.fr/programmation/fichiers/cpp-objc-en.pdf</a><p>It goes through step by step and explains how the OO terms you know map from C++ to Objective-C, e.g., "If you want to declare a static class method, you use this syntax..." If you're familiar with OO in general it's pretty good, too.<p>It really lowers the Objective-C syntax hurdle, IMO.
Besides of this course from MIT and the one at Stanford (<a href="http://www.stanford.edu/class/cs193p/cgi-bin/index.php" rel="nofollow">http://www.stanford.edu/class/cs193p/cgi-bin/index.php</a>), what other sources are you using to get into iphone development?