I currently run a 5 box setup with 1 prot pally 3 ele shamans and a resto druid.

Some people use the healer as the main so they can diresct heals to the dps bot in say a mage/warlock priest setup but in my case i direct dps by controlling the pally as my main and realisticallly using the druid as a healbot for the group.

My first order of business is to unbind every key in the wow interface except movement keys and the main actionbar keys which are 1-0 ,-,=. I use ct-mod to arrange my bars on all my toons.

I use a setfocus macro with modifiers that can switch foucs to any of my toons such as: /focus [modifier:ctrl, target=healnu] [modifier:shift, target=kowhealz] You ahve to setup focus macros for all your toons so that when you want you can change focus and heal everyone that way with a dedicated healing button or you can do a combo like I do:

I use a g15 keyboard and I use the keyboard software to assign random keys on the keyboard to the g 1-18 keys I use these keys combined with macros to heal any party member using the druid by pressing a gkey in a particular row. These are all bound on my druid char. I also have my focus targeting macro setup so that if my main pally targets a person that is a player or even a member of my own party or raid that my healing spells will target what my pally is targeting and cast on them. This is nice when runnnig around with my main i can click on players and hit rejuventaion and a lifebloom and never break stride or switch chars. My shamans have a dedicated lesser heal focus on my tank which when pressed makes all three of them hit me with lesser heals at once pumping me up to almost 7k life instantly if they all crit and thats at lvl 70 in shit gear. My pally tank is 80 and all epic with almost 27k life. I never have a problem staying alive or killing things. The hardest part is coordinating your mains buttons to gain the best combos of spells to cast on mobs all at once. I try to hit mobs with a bit of everything. I press 2 and each of my shammies casts, flameshock, frostshock, and earthshock all at once on a mob or if I press alt 2 they all blast the target with flameshock. The macros setup is a chore and you will spend a fair amount of time and effort to get them all right and the bugs worked out but when you do its a great thing to pull 15-20 elite mobs pop down 12 totems cast chain lightining and lightning bolt over and over again and keep your whole group healed by pressing 6 buttons. The next thing i am working out is reaction time and actual postioning of my chars during boss fights where the encounter lays out pools of poison or other aoe effects that linger because you can have them on follow but this becomes a serious problem with classes that cant take 2k a tick for very long. I am going to try pimping my healer out with all the threat reduction enchants and abilities as I can and basically worry about my tank and healer positioning and if my dps dies so be it. If you have any macro questions or healing questions let me know.