This is a copy of a post I originally had in Codecademy Forums years ago.
I thought I would post it again so people can benefit from the linked material; as it was made so long ago CC has since made some of the courses listed such as SQL and Java but for completeness I will leave these sections in so people have additional material they can use.
If you use any other good sites add them to the list, this post is a
wiki so click on the little green pencil in the top right to add to the list.
This is a great list of resources for learning languages we don't (yet!) teach, compiled originally by Patrick. Have others? Post them below!
Objective-C (iOS and Mac)
Objective-C from Cocoa Dev Central
Apple's Objective-C intro (you'll need an Apple Developer account, it's free)
Stanford CS193P Look under "more from Stanford" for iOS 5 updated versions. Also covers MVC basics that some have expressed interest in.
TheNewBoston's Objective-C Tutorials
Stanford CS106A Awesome class. It covers Java but more importantly it covers program design theory that many people have asked for. It can be followed up with CS106B and CS107 also available on that website, for more theory combined with (non-Java) practical.
TheNewBoston's Java Tutorials
Oracle's Java Tutorials
Practice-it Java practice
Programr (too many to list)
CodingBat (Java and Python)
Marakana Bookshelf (too much to list)
Marakana's Youtube channel (more advanced but great, too much to list)
The New Boston
A quick shout out to those who contributed the original links. Thanks guys.