De cabo a rabo, literally, from the end to the butt, from the stub to the butt, from the tail to the butt - in English, from beginning to end, from start to finish, from end to end.
He leído de cabo a rabo revistas sobre lo último en equipamiento.
I've read all the magazines on the hottest equipment.
In Puerto Rico there is a university that we always used to make fun of the name - Universidad del Turabo. If you say "de" instead of "del", it's University of Your Butt...
You might also hear occasionally, de pe a pa which means the same thing, or from A to Z.