Seeing as you are just starting out, I'd be pretty cautious about attempting right from the start to multibox so many chars.

There are so many things to consider with so many classes:

-Cast times
-Aggro
-Mana efficiency
-Synergy (e.g. Curse of the elements from lock for mage, or curse of shadows for a shadow priest?)
- Some pretty complex keybinding/macro creation

From personal experience, I started out with a Druid, Shammy and 2x Lock. After boosting them to 25 or so I tried them out solo in various instances and it went ok. I had three basic functions to worry about, Tanking (manually controlled), Heals (basic F1-F8 macros), and DPS, simple dot cyles on Locks.

Since then I've been running a new 4 man shammy team and it's simply easier and more efficient. I'll most likely incorporate elements of my old team or pre-existing 70s at some point, but the learning curve is still fairly steep, but I'm getting there.

However, with 5 chars the whole setup is liable to be pretty complex, it'd be worth studying which spell casts time well with eachother given the right investment in talents.

My advice, give it a try, but you'll probably have less frustrations building it up as you go. E.g. try 2x1 class and 1x another to start with, play them to 20 and see how it feels. If it's going smooth, add another etc.


So far, I've yet to see much evidence of people effectively running 5 boxes with 5 chars in tough circumstances. The closest I've come across is Skarlot here on these forums, take a look at:

Skarlot in Shadowlabs: http://www.dual-boxing.com/forums2/viewtopic.php?t=2193

However I'm pretty sure that has taken some serious practice to get to that stage.

Good luck,

cheers

Ky

EDIT: It also depends on your aspirations, you could easily 5 box various char classes, at about 60% efficiency with not much effort at all. E.g. Questing, grinding: Priest Smites, Druid Wraths, Mage Fireballs, Warlock SB's, Shaman Lighting bolts, Warrior tanks. You still kick out a hell of a lot of DPS, but it'd be neither exciting nor challenging really, but you'd get to 70 in the end.

If you wanna pvp, forget it. and if you wanna do Pve instancing at high levels, be prepared to do a lot of planning and practicing.