All about Looping is a fictional guidebook written by the Admins Saraswati and Iris and edited by Seshat. Written as the Admin response to Loopers common questions, it is more commonly known as Looping for Dummies.
Although the book itself did not exist at the time, the first time that Saraswati thought to create such a thing was when explaining to Aura why the Loops were happening, becauase the Anchor managed to crash her first Loop almost immediately after it began. The Admin realized that by showing up herself she managed to instill a sense of doom into the Looper she was speaking to, and decided to see about coming up with a friendlier way of explaining things in the future.
The book made its first actual in the Log Horizon loop, where it was added as an addition menu to the loopers status screen. The concept went dorment after a while, as the admins found the usual "Welcome to the Multiverse" speech was usually more than enough to not fully necessitate it. However, it was eventually handed out by the Admin Ihy during the first Fused Loop between the two Spyro the Dragon Loops. Ihy was made to do this by other Admins as they felt that someone would need to explain things to the Spyro Loopers and it both had to be Ihy due to his status as Spyro Admin and couldn't be Ihy due to his predisposition to be a lazy drunk.
Since then, the concept has been rather debated by Admins over whether it needed or not. Some find the cocept of having it being the first thing in a loopers subspace pocket useful, as they wouldn't have to wait for a fused loop with a more experience looper to find out what's going on, and it covers all common looper questions and concepts. Others still find it not necessary, as the multiverse speech still manages to cover most of everything, and takes less time away from the repairs to Yggdrasil.
Chapter 1: Is Your Life Too Repetitive? Looping and You
Chapter 2: Help, My Part Has Changed! Loop Variants
Chapter 3: You Are Not Alone - World Tree for Dummies
Chapter 4: Luggage for Loopers! Making a Subspace Pocket
Chapter 5: Tenuous Grasp on Sanity? Useful Tips and Tricks
Chapter 6: All the 'Do Not's - How to Avoid Breaking the Universe
Chapter 8: "High Variance Loops"
Log Horizon Loops, post 1: 
Spyro Loops, post 30: http://forums.spacebattles.com/threads/spyro-the-dragon-loops.292449/