Are you teaching a new grade level or subject this year? If so, you likely do not feel like you have had enough time to plan.
Three years into my teaching career I moved between campuses and inherited a book cart full of textbooks and supplemental materials for my new assignment. I had no idea whether the materials were current or well-aligned to the current standards for the course! To make things more difficult, I was a singleton teacher and had no one to ask. It took me a long time to wade through what I had, and I am quite sure that I was missing components of the material that came with the original purchase.
If you are in a similar position, consider these suggestions to help you plan instruction efficiently with materials you have inherited.