Xavier Amatriaian created some of the best basic tutorials:
the biggest one was from a recsys summer school: https://www.slideshare.net/xamat/recommender-systems-machine-learning-summer-school-2014-cmu (2 hr video here: 2hr video )
He has been prolific afterwards:
the-recommender-problem-revisited
and
lessons-learned-from-building-reallife-recommender-systems
Every recsys conference year has a set of tutorials. Most of them have slides: https://recsys.acm.org/recsys18/tutorials/
Microsoft has a working code repository to stand up a recommender system on azure, leveraging databricks and their stack: https://github.com/Microsoft/Recommenders
Seminal papers here: https://github.com/YuyangZhangFTD/awesome-RecSys-papers