Where to find it
Open your character window (default C) and select the Statistics tab at the bottom-right side of the character interface.
What it tracks
Total kills and XP/honor kills
Honorable kills by battleground and world
Killing blows
Creature and critter kills
Boss kills
Largest hit and heal
Total damage dealt / received
Total healing done / received
Talent tree respecs
Darkspear Islands PvP stats
Beta note: boss entries only become visible after the character has defeated the corresponding boss at least once.