#2 - Feb. 1, 2013, 4:21 p.m.
It's been a long time since the Looking For Group channel went away. On this day and age, you can group up with strangers to run content through the Dungeon Finder, Raid Finder and the Random Battlegrounds.
If, on the other hand, you're looking to create an organized group for, say, Challenge Modes, it might be a good idea to check your realm forum and make sure the people you want to run this content with has the level of skill you're looking for. Grouping up with complete strangers for it would probably end up being a disaster if you can't work as a team :)