So I just hit 50, what's next?

[Demichelis]

Now, coming from WoW, I'd figure the most logical option would be to gear up for raids and such, but as I'm scrolling through the Achievements page and the Summerfest event going on, there is a lot to do and I'm not sure what to do or where to start. I'd like to gear up via experts, but I'd also like to tackle some of the achievements, like the Water Saga quests and some Plane achievements, etc.

What's a good recommendation for someone like me on where to start?

[Tarien]

Start with the Attunement Chronicle (press J), do the others too with a friend, that should net you some nice 50 blues. Buy any gear you can afford, and get rolling with the dungeons. Also keep an eye out for any invasions in Ironpine Peaks, Shimmersand, Stillmoor or Ember Isle, and go partake in those. In any spare time between those do the world event stuff or the life/water saga. Once you're mostly in Expert level gear have a look at doing the Ember Isle quest line, rewards are nice.

[Psilo.]

If theres and event on, find out what Greater Essences it is you need to collect, check the event vendor if there are Greaters there that match up. Close rifts for currency.
Do this before the event is over, I forgot to do this last event and have been running with really lame Greater Essences - for me only event vedor had my BiS ones, think they are round 500 of whatever the event currency is. The lesser BiS essences are bought at the normal essence vendors at about ~100 inscribed Sourcestone cost.

[Umanarav]

Planar Attunement.