A powerpoint of the OLD syllabus – much is still relevant though.

A nice introduction to how the kidneys work (from TED-Ed):

Mr Paul Andersen (from Bozeman High) describes Osmoregulation (including in fish which you don’t need to know) in a 8m 57s lesson.

An animated tutorial from McGraw Hill Education on basic Renal processes and here’s an animated, narrated tutorial on the mammalian kidney which also includes a quiz (from Sinauer Associates).

In Crash Course Biology #29 – The Excretory System: From Your Heart to the Toilet, Hank takes us on the fascinating journey through our excretory system to learn how our kidneys make pee.