Online resources.
Open problems in Dynamical Systems & Ergodic Theory.
Online notes on Ergodic Methods in Additive Combinatorics by Bryna Kra.
Online notes on Ergodic Theory by Terence Tao.
Online notes on Ergodic Theory by Ben Green.
Online notes on Ergodic Ramsey Theory by Carlos Matheus.
Online notes on Ergodic Theory by Tim Austin.