Good for a general classroom site (more for elementary but can be modified for secondary or clubs) 

Good instructional website to serve as a companion for Google Classroom

This amazing site acts like a template and demonstrates the possibilities of what you can do with a Google Site. However, it also describes how the content on the sample site was added (often with videos). It is a wealth of information. Check it out!

This is an example/template of a site you can use for a single or group of students with an IEP