Roll overview and masterlooting
Clicking on the minimap icon will show this window with an overview of all rolls. You can also become or search for a masterlooter and check the current masterlooting session in the lower right corner.
Rolling on loot
Looting items that you (or someone else) might be interested in pops up a standard roll frame where you can choose if you need it or not.
Actions
You get a handy little overview of all the things you should do, like asking for, trading, awarding and voting on loot.