The honor points you earn from battlegrounds and world PvP, and conquest points from arena and rated battlegrounds can be redeemed for PvP armor sets, trinkets, rings, and many other items.
Horde players can redeem their honor and conquest points at the Hall of Legends in Orgrimmar. The Hall of Legends is located in northwest part of the Valley of Strength, on the higher tier. Any city guard can mark the location on your mini-map.
If you're Alliance, you will turn in your honor and conquest points at the Hall of Champions which is located in Old Town near SI:7. Talk to a nearby guard to mark the Hall of Champions on your mini-map.