Rated battlegrounds are arena-like 10 vs. 10 matches on regular battleground maps introduced with the Cataclysm expansion. As of Patch 4.1 (although this may have only been a server-side change), groups of the same faction can join to battle each other.
Conquest points will be awarded as you win games, not every Tuesday, or Wednesday if playing on European servers. Limit to maximum amount of points each character are able to gain per week. This limit is based on your rating; the higher your rating, the more points. The highest rating ever earned is used to calculate maximum amount of points you are able to earn.
Starting with Patch 4.2, every time a character wins 75, 150, or 300 Rated battle grounds, a special epic, ground mount will be mailed to the character. This mount is bound to the Battle.net account so it can be mailed to alts before it is used and added to the characters list of mount summoning spells.