Aruba has free online eLearning training for the InstantAP! This training has been available for some time but had just been updated for some of the features of IAP v.4.0 and v.4.1.
There is both an IAP version and IAP + Central version and they can be viewed here:
http://cloud.arubanetworks.com/instant-training
http://cloud.arubanetworks.com/central-training
The first 17 modules are based on earlier IAP 3.4 but the concepts are valid. More updates will be coming with each new major release.