Repeating what most folks have said: I used the 1-60 RAF guide that is posted on this site which is supposed to be easier for multibox and skips most useless collection quests(sorry I forget the name) and once at outland I kept using the default Tourguide/Jame's leveling guide. I have the lightheaded addon which accesses wowhead right from the quest window so I would take a collection quest and see if it lead anywhere useful or if it had good gear. Unfortunately, getting to Northrend I've found that collection quests are pretty hard to skip and so I just sucked it up and resolved to do the zone achievements for Loremaster.