In no particular order, these resources are great for taking a deeper look into problem solving resources.
Vermont Agency of Education: Problem Solving
Illustrative Mathematics
Michigan Council of Teachers of Mathematics: Rich Math Tasks
NRICH
Math Landing
Dan Meyer: The Three Acts of a Mathematical Story
Vermont Agency of Education: Problem Solving
Illustrative Mathematics
Michigan Council of Teachers of Mathematics: Rich Math Tasks
NRICH
Math Landing
Dan Meyer: The Three Acts of a Mathematical Story