I have found
www.lynda.com to be a great resource. Training in software is always expensive (especially Adobe products) and with lynda.com you pay a low monthly subscription fee that grants you access to a ton of streaming training video. It's great for essential training plus some more complicated things, and from there you can delve into more advanced training from other sources.
I've always had difficulty with jumping into advanced training without knowing the underpinnings, and that's where lynda has helped me out enormously.