GW2 has a number of group events spread all over Tyria. These hand out rewards in the form of items and ascended crafting materials.
Dulfy has a constantly updating timer page showing which events are on, where they are, and what rewards they offer. (http://dulfy.net/2014/04/23/event-timer/)
You can gain quite a bit of money, gear, and skins doing these. To link yourself a waypoint, copy this type of text: [&BEYAAAA=] , and paste it into your chat (GW2 allows self whisper) and it should create a waypoint link. Once you click on it it will show the waypoint in question. Sometimes if the event has started, the waypoint is contested. In such a scenario, you will be teleported to the next nearest waypoint and walk the rest of the way.
The rest of Dulfy's webpage has other GW2 pages which are quite handy to know about. Feel free to browse through and learn!
When I'm around, I usually do some of these so feel free to tag along.