Leveling from 1-60 in a group

[Baalls]

The game is meant to be play with other people. You will have more fun. NPC's will die faster, easier, but you have to collect twice as many items for quests. This is not a problem because in vanilla there is often "dead-zones" where you may right out of quests and be forced to grind. If you have two or more classes that accentuate each other this will be great.

[Garfunkel]

You never run out of quests. You might have to jump around zones a bit but if you do each quest in a zone when they are yellow/green, you will not run out, 100% certain. Usually the quest-shortage problem comes when a player isn't aware of semi-hidden quests and ends up doing orange/red quests which then impact them few levels later. It might not be the quickest or most efficient method - 100% questing - but it's certainly viably without grinding at all.

Anyway, grouping is not a problem at all and does make leveling much more fun and enjoyable. You might want to use a vanilla database like http://db.vanillagaming.org to check all quests available at each zone to ensure you don't miss out on any and maybe even plan them out a little. Sure, the gathering quests will take you bit longer but that's compensated by the fact that you can do kill quests so much quicker and also because you can do all elite quests quickly. Don't skip on dungeon quests either, they always give great XP!

[DeeMarie]

If you're willing to use all three zones you get at the appropriate level you won't run low on quests. But in my experience - I'm levelling with two guys who have never played WoW - we are getting low on options as we've stuck to just two.

With two people though, if you're using rested, you should be ok. Make sure you pick a good combo and have fun