I've been lucky enough to have had access to resources throughout my career, that not everyone gets to use (primarily the great team I worked with on the old forums). In addition, I've had access to specialized training for partners, which of course I only had after taking my current job.
I'll depart from normal soapbox, to say I personally don't get much out of the standard courses. Not to take anything from the instructors or those who write the material, however the courses HAVE to be held to the lowest common denominator. An instructor may not know for at least a day or two the overall skill level of his audience (and that of course is based on participation). The standard courses are needed, and are an important part of the overall training and lifecycle, but they just didn't help me much.
The one exception would be the advanced training I took for Notification Server (6.x). Everyone in the room was a skilled admin, and there was an incredible wealth of resources available to us. I hope to see that type of course generated at some point in the future.
Much like stated above, my number one learning opportunity has been using the product. Followed by running into brick walls, and then perusing the forums, juice, kb system and altirigos and seeing what other people were doing.
Altiris\Symantec have a vibrant user community, and I feel that is the number one resource available to all. (ok, so that was my normal soapbox).