This guide shows how to work with the btrfs file system on Linux. It covers creating and mounting btrfs file systems, resizing btrfs file systems online, adding and removing devices, changing RAID levels, creating subvolumes and snapshots, using compression and other things. btrfs is still marked as experimental, but all those features make it a very interesting and flexible file system that should be taken into consideration when you look for the right file system.

http://www.howtoforge.com/a-beginners-guide-to-btrfs