While are many people with level 70's out there especially since the TBC expansion has been out for more than a year already, I'm sure there are lots of people who don't or at least just did and don't exactly know what to do. I was sitting around in Shattrath City earlier when someone asked the exact thing in trade chat, hinting that there might be a lot of people out there like this guy who don't know what to do when you first hit 70. So what exactly do you do? After allocating your last remaining talent point an buying your level 70 skills, these are things you may want to do when you hit 70.
1. If you've got the gold to spend, it would be really helpful to buy your flying mount right away. This could help in your mining and herbalism while also giving you access to places like Skettis, Ogri'la, Elemental Plateau and the Tempest Keep dungeons.
2. If you don't have the gold to spend or just want more of it, then it's really helpful to do the Shattered Sun Offensive daily quests. Ogri'la and Skettis requires you to have a flying mount to reach while the SSO dailies don't except for the quest Intercepting the Mana Cells, which you do in Blade's Edge Mountains.
3. Group quests in Netherstorm and Shadowmoon Valley normally have great quest rewards that could add to your starting gear as a fresh 70.
4. If you're a clothie class and a tailor, investing time to farm the mats to make your Spellfire/Frozen Shadoweave/Primal Mooncloth sets.
5. As you're looking to gear up, PvP epics are generally a nice way to go to get yourself ready for higher content. BG and Arena gear are great at plugging those holes until you get a good PvE equivalent from Karazhan or Heroics.
6. I'm assuming that as you've leveled up to 70, you must have achieved honored rep with at least some of these factions: Thrallmar/Honored Hold, Cenarion Expedition, Keepers of Time, Sha'tar, and Lower City. These factions have a decent starter pvp set which could also be great for PvE.
Druid
Feral Dragonhide Battlegear
Resto Kodohide Battlegear
Balance Wyrmhide Battlegear
Hunter Stalker's Chain Battlegear
Mage Evoker's Silk Battlegear
Paladin
Holy Crusader's Ornamented Battlegear
Ret/Shockadin Crusader's Scaled Battlegear
Priest
Shadow Satin Battlegear
Holy Mooncloth Battlegear
Rogue Opportunist's Battlegear
Shaman
Enhancement Seer's Linked Battlegear
Restoration Seer's Ringmail Battlegear
Elemental Seer's Mail Battlegear
Warlock Dreadweave Battlegear
Warrior Savage Plate Battlegear
7. Of course you still have to do dungeons so that you can get nice blues to get you ready for Karazhan and heroics. Don't forget that while it's no longer required that every member of a Karazhan raid have the master's key, it's still nice to do the quests to get it. The quest chain brings you to some dungeons to get some gear and also the quest rewards afor the chain are pretty good too.
8. Rejoice and be glad that you have a level 70! To all of you guys who just got to 70, congratulations and have fun!