Thanks for all the info, guys!

I will now see with my friends what they think is best.

How much time would we need to meet up?

What level should we get to before grouping up?

Time to meet up would depend on where everyone is starting, of course.

If you're starting around Qeynos...
Erudites would take anywhere from 20-40 minutes to get there (depending on where the boat is when they get to the docks).
Barbarians probably 15 minutes, more without sow. Without sow they'll likely need a few levels on them to run through Blackburrow, unless someone has the tunnel cleared.

If you're on Faydwer, gnomes and dwarves can run to gfay in under 10 minutes.

If you're aiming for EC...
Ogres and trolls have a bit of a run through 4-5 zones. (Feerrott, Innothule, SRo, Oasis, NRo, EC)
Halflings just run through a few zones. (Kithicor, WC, EC)
Dark elves are easy (Nek, EC)

As to what level, probably 4-5 is good... enough for your casters and priests to get their second circle of spells. Erudites should probably just head straight to Qeynos... their newbie yard sucks, and Qeynos has all their spells.

Remember also that in Faydwer gnome necros will have to return to Ak'anon for spells, in Qeynos barb shamans will have to return to Halas, and in EC ogre/troll shamans will have to make a spell trip. For the ogres and trolls, try to pick up Spirit of Wolf before you leave home, even if you can't scribe it yet.