mebro:
There are also a several good study guides for the ATP knowledge test available that you may find useful if you find you have any energy left for self-study after those long days of flying. I found the red books by Irvin Gleim to be well organized and most usable. Whether you attend a traditional ground course or not, the self-study will pay off. No short course is designed to do anything more than prepare you to pass the knowledge test, so any lack of "depth of knowledge" will not really be addressed by a ground prep course or study guide. The Jeppesen text books (expensive!!) go to greater depth in exploring the subject areas as they are more in the character of a college text and may enrich your command of the subject areas to some degree. Preparing for the ATP is quite a bit of work, but it sure will feel good the day you fold that new temporary certificate up and put it in your wallet! (be sure the ink is dry first)
Best of success to you,
Westhawk