Former Player Returning- Help Needed

[Sylvaeres]

Hello. I recently returned to the game,while missing most of Cata. I'm looking for help on a few basic questions to get me back into things. I play a Horde Mage, with multiple alts that will be max level once I get situated

1) What should I do once I hit level 90 to get caught up?

2) What are ways where I can make a decent amount of gold to get myself started?

3) Any major changes to the game which I would have missed?

Ty ahead of time for any and all help. It is much appreciated

[Ankunegg]

1) chain queue heroics then LFR
2) questing to 90
3) not really