What Mental said...
To worry about getting depressed if your levelup takes some minutes/hours longer is just wrong. In my book your priority system is seriously messed up.
Well, to be fair, after doing this type of leveling 15+ times, it gets old after awhile. But the OP is talking about being a new player, so that doesn't even apply to him, he's not even seen the content yet.
With the new systems in place, OP, all you have to do is..
1). Go to Orgrimmar/Stormwind City.
2). Find the Warchief's Command or Hero's Call Board respectively.
3). Take the bottommost "Hero's Call:" quest.
4). Go where it tells you to go.
5). Do quests as you get them.
You literally can't lose. The minimap tells you where nearly everything is, if that fails, read the quest dialogue.
From 1 to 58-60, the quests all lead into one another, there's no need for any "Guides". Outland is a lot less linear, but still isn't THAT hard.
Northrend is pretty easy too.
Or, try this: Open your map and zoom out. Mouse over all the zones. Note, they tell you what level range they are. Pick one that's yellow to you (-2 to +2 levels). Go there and check the areas with Flight Paths for quests.