CK-12 is one of my favorite resources for educators. It contains a wide variety of materials, lesson plans, virtual labs, interactive lesson activities, digital-multimedia "flexbooks" and much more.
CK-12 also has a certified educator program for teachers. It is a comprehensive program with thousands of educators around the globe. They have some great free webinars coming up from July 8-19, 2019, where you can enjoy free, fun, flexible learning. There are over 30 live sessions so you can create your own learning pathway. To earn the CK-12 Certified Educator status, you need to watch 5 live webinars, watch 2 on demand sessions, and create 7 matching assignments. The program offers professional development hours, engagement with live CK-12 moderators, extensive knowledge of the CK-12 platform, and a network of educators. All free!
Take a look at CK-12 and the Certified Educator Program.
More resources on CK-12