Newsletter
From Learn to be a true Social Engineer
Otherwise you can look for archived newsletters here. Usually they will show up about 2-3 weeks after the public release.
Social Engineer Newsletter - Volume 2 Issue 10
Social Engineer Newsletter - Volume 2 Issue 9
Social Engineer Newsletter - Volume 2 Issue 8
Social Engineer Newsletter - Volume 2 Issue 7
Social Engineer Newsletter - Volume 2 Issue 6
Social Engineer Newsletter - Volume 2 Issue 5
Social Engineer Newsletter - Volume 2 Issue 4
Social Engineer Newsletter - Volume 1 Issue 3
Social Engineer Newsletter - Volume 1 Issue 2
Social Engineer Newsletter - Volume 1 Issue 1