Horde only, go to Grizzly Hills and find the mobs named
Conquest Hold Berseker,. they cast an ability called Battle Shout - Spell - World of Warcraft . Simply stand near the mob, it refreshes the buff every 20-25 seconds. Wait until your bg que pops and wait until like the last second to zone in. Alliance could theoretically bring a priest with Mind Control or engineer with a mind control cap if they wish to gain access
1str=1 Attackpower
So thats like 332 Extra Strength
Right now, my lvl 85 twink has 780 Attack Power...the Mob gives me 332 ..thats effectively a third..for a lvl 85. Stacks with your 10% AP shout if you are a warrior as well..imagine a lvl 29 prot pally or something..one shots inc lol