Are you in the ADC because your’re in the server/network admin track? Or did you just sign up on a whim?
Learning to program is basically free (if you use your local library to check-out the books). If you just want to learn a good all-purpose language then Python might be a good choice. There’s a great intro to programming course from MIT on iTunes U: OCW 6.00 Introduction to Computer Science and Programming which is taught in Python.
One of the biggest benefits to learning to program with Python is that it’s a very clean language that handles some of the uglier details from you. You can eventually move on to other languages where you can really drill down into the knitty-gritty after you master the basic concepts of how to solve problems using variables, operations, conditionals and control structures.
The other approach is to start with a language like C which is harder to learn, but doesn’t hide things from you and gives you a much better sense of what is going where in the machine. Some people learn better that way. Masters of the Void is a great tutorial for getting started learning C on the Mac. You will still want to work through a real book on C though.
If your goal is to write native Cocoa, or iOS apps, then you’re going to need to learn Objective-C. Objective-C is a strict superset of C which means that any valid C code is also valid Objective-C code, but there are extensions to the C language that allows you to program using objects. The book to get for learning Objective-C is Steven Kochan’s Programming in Objective-C 2.0. It’s the book I used to get started programming. The Kochan book will be focused on command-line apps (you have to walk before you can run). For GUI apps, you’ll want to move on to Aaron Hillegass’ Cocoa® Programming for Mac® OS X.