There's no specific step by step guide available for multiboxing although some people made some pretty informative info about them.

When I leveled my four shamans in TBC, I had a warrior+4x shaman box, when I reached 31 the low level and extremely boring instances (you'd do them like 10 times in a row etc, it's very annoying.) I got too tired of it, so I dropped the warrior and had my lvl 70 enhancement shaman boost my four then level 31 shamans. I leveled from 31-60 boosting in instances in no time. Went really quick, at 60 I decided to level through quests. Since Outland is quite a bit better then Azeroth. I dinged 70 with 11 days played time on the clock. (I'm anything but a powerleveler, so it's a really fast time for me. :P )

As far as questing in Azeroth (1-60) goes, it's a bit of a pain, if you avoid collection quests you'd find yourself traveling a lot. If you got RAF, then questing, even collection quests, will be worth doing. I'd suggest you just put up with them and quest for the fastest way, if you don't have a high level on a fifth account to boost your four characters.