Some people have been saying that if you do 25 dailies you'll level faster... etc etc.
But I think that you would level slower, because you would then be BEHIND everyone else in the first quest (and get stuck on gathering quests).
Instead, I suggest that those of you who are going for realm firsts, get a friend to pick up the quest, and share it, while you're training flight master's liscence, and get ahead of the croud, then you could outlevel everyone and have the spawns/mobs/quests all to yourself.
These are the fist quests: http://www.wowwiki.com/Quest:Hero%27s_Call:_Mount_Hyjal! (for alliance) and http://www.wowwiki.com/Quest:Warchie...d:_Mount_Hyjal! (for horde). They are the boards that give quests located in the front of the major citys.
PS: been lurking for a long time, wanting to contribute badly... So I know this may be not enough to matter and then useless, if so I'm sorry. Just wanted to contrib for the first time ;P