Two things will help you: Macros, and a mouse with extra buttons. People will recommend the MMO Naga, but I personally find that to be a bit too cluttered. The RTS Naga is quite good (only 6 buttons) and you can use alt/ctrl/shift modifiers with them giving you up to 18 buttons. I don't use them all, but they can be quite handy with mouseover (<mo>) macros. I also use Place and Heel on those mouse buttons.

Other handy keybinds - always have a button to swap to target of target. That'll make it easier to swap between a boss and the tank. You'll also want Set Focus for macro use.

Some other handy macros for my DPS rotations as SCH include all my DoTs, Energy Drain, Virus, and even Bane to cast on these priorities: Target, ToT, Focus Target. This will ensure that my offensive abilities cast on a boss without having to move my target from the tank.

Hopefully that helps give you some ideas of what you can do.