This sound awful to say but I can't help you but would love to pick your brain on design anyway if you're open to it. Particularly since I have no background on the stuff you're looking for.
I did find some website tutorials online but I'm not sure they are helpful or maybe its just I'm not getting it.
The thing is, there's no such thing as "website design centric" techniques in Photoshop, except maybe the effects palette (but you can learn 90% of that just by playing around with the options).
The effects palette aside, all you need for web design is the typographic tools, vector shapes, and rulers (to set up your grid). So you can basically learn the technical aspect of "Photoshop for web design" in 30 minutes.