The NGSS classroom resources database has many lessons and activities that have been vetted by the NSTA as well as user submitted materials.  http://ngss.nsta.org/Classroom-Resources.aspx

The NGSS is more than a resource or someone's opinion on science education; it is the result of years of research and collaboration among education leaders and professional researchers.  If you would like help with any of these, or other activities, contact the district STEM team.