Teaching with Higher Order Thinking and Rigor in Mind (formerly Connecting Extending Thinking, v.7) is a great resource to show you how to deliberately teach thinking skills to students while increasing rigor.
--One of the books we rely on the most as a supplement to our rigor workshops is Teaching with Higher Order Thinking and Rigor in Mind. If you want to learn how to deliberately teach thinking skills to students, this is the book for you.