I just added a new BTRFS section to my Wiki,
Is a collection of links to a variety of BTRFS topics...


BTRFS stuff in my links...
General info about BTRFS like the SDB and ArchWiki
A link to what is considered the most authoritative blog about addressing "Filesystem full" errors. Unfortunately, it's highly technical so I doubt many will understand what is described but it does contain a number of strategies which can be used, even blindly to recover a system from this common error. Some are even simple tries. Maybe one day I will compile those commands into a simple list of things to try (or someone else with some ambition can do so).
An important section on resources for setting up, managing and recovering degraded BTRFS RAID. I consider this significant since BTRFS can probably be a viable alternative to LVM and other software RAID (dmraid and mdmraid). In fact, I'd expect some smart Users to start setting up their RAID in BTRFS instead of conventional ways.

If anyone has other recommended BTRFS resources, go ahead and modify my Wiki or suggest it so I can add it!

PS. I posted my experience converting a TW BTRFS root partition from a single disk to a RAID10 across multiple disks. Those who want to simply mirror (RAID1) would be little different.