Instance boosting was my perfered way to level my team of 4 on my raf.

Here is the path I followed using a lvl 70 paladin to boost with in season 2 gear

RFC (Org) - Lvl 8 till you hit lvl 12 (you can basicly skip this and just grind in the newbie zone and just outside it till you ding 12 if you like doing those silly easy quests)
SFK (silverpine forest) lvl 12 to 25 basicly ... if you park all your toons by the gate your main can run around and pull all the mobs in groups above your toons threwout th entire instance
it takes me 3 pulls max I think to clear this..and if your worried about blue's u can set masterloot and move the blues to toons that need them that way. I seldom
Looted in this instance simply for speed reasons..just stood in place and pulled and repeated each run takes less then 15 minutes.
SM Cath (UC area) lvl 25 - 40 - I found the xp was a bit low as I started this but as the toons level up you gain more and more xp per kill...I can 3 pull cath with ease, if you target the
boss in cathedral he'll pull the entire instance for you.. I usually leave my guys in the fountain well main rounds things up.
ZF (gadgetzan) lvl 40 - 50 - this area is awesome for boosting in...drag your guys into instance park em by the door, have your main hop onto his/her horse and round em up
If after combat you can't remount it means you forgot to kill someone..usually a caster..this is a glitch GM's have told me..kinda lame but go back and kill
some straggler and wayyou ago again..this instance is very fast to run even full clears for me.
Scholo (WPL) lvl 50 - 60 - Some ppl choose strath, I perfer scholo I dunno why it just closer I guess once you fly to UC and run...anyways some good blue drops, and its basicly really easy
I can't remember how long each run takes but I burn threw the levels usually in a night from 50 to 60.

Enjoy, and welcome to the club.