really it'll just take practice, but personally i find in a fight i always rotate storms eye and the butcher's block combo, and alternate to storm's path instead if i know there's plenty of incoming damage. Best ask your healers if they need it, or try and judge on the situation.

Tank swaps, best to have a macro so your other tank knows when you provoke, and stand with him in front of the boss before you do. then the boss wont turn and your tank will have an idea of what you're about to do if they see you standing with them.

As for tanking guides, really its only the mechanics you need to know which are explained. cooldown micro-managing is something you have to learn and people have different preferences for rotating their cooldowns. you'll learn things like during Nid-ex, when he's casting hot wings and tail he's not attacking you so if youre wary of going deliverance, it wont hurt at all to swap in for that. one thing i often do is thrill of battle before swapping into deliverance, not after because its a higher hp cushion (20% on top of defiance's 25). or berserk and bloodbath to help negate some of the boss' auto-attacks, when i know i can comfortably get back into defiance before the tank buster comes