Depends on time of day (after school hours the queues are shorter but there will be more genuine Trial players, meaning a lot of camping takes place, same at night when the 24's are out in force), but generally speaking Alliance BG queues are between 15-20 minutes and Horde queues between 5-10 minutes.
As far as LFD queues are concerned, Horde generally has shorter queues as well (about 10 minutes tops as DPS) and the group is more prone to remain intact, as Ally finishing a Dungeon isn't exactly a given.
