Lesson Planet: Project Based Learning Teacher Resources
From the OER: "Founded by educators for educators, Lesson Planet is passionate about creating and delivering innovative digital tools and quality educational resources to help personalize student learning and inspire great teaching. For over 20 years, Lesson Planet’s team of experienced teachers have been curating and reviewing online, free and open educational resources (OER), as well as building tools that help educators save time discovering, planning, and implementing their curriculum."
Each collection lists Project-Based Learning (PBL) lesson plans and is separated by grade level. There are articles for best practice implementation for different PBL projects.