dailies first, unlock Icecrown dailies, then argent tournament dailies (NE Icecrown) do quests, earn badges and afford new weapons for everyone (takes 2-3 weeks doing then daily) - this a) earns you some nice money b) will help getting some gear for everyone via Ebon Blade rep. Or do instances and gear that way. Or do what I do and spend all your dailies money on gearing tank from AH/crafting THEN do instances and gear everyone else up.

Or do whatever you want. Getting to 80 is an achievement in itself for people with RL's so stick to what's fun.

And GRATZ!