Our studio just moved over to Nuke as one of our main compositing applications.

A render license will not help you, as that is for render farms. You can't do anything with it, but render. You can't open the main application, compose shots, etc. It just picks up jobs and renders them.

There is a PLE version of it, that should be fine for your course. Otherwise, you'll have to pay £2,300 for a full license. Educational pricing (I think) exists as well.

FXPhd, and Digital Tutors are good for instruction. However, a lot of it will be found by trial and error, and web forums.