This site has many wonderful resources for creating Google Sites by Flipped Education. The instructions on this site are for using the standard Google Sites - not the new Google Sites released in August 2016.
Student Portfolios with Google Sites
Advantages of G Suite for Portfolios
Google Sites integrates with all of the other applications
G Suite users already have accounts
Easily embed everything from YouTube to Google Slides
Drag and drop interface that is easy to use and professional looking
New features make it even better with buttons and layouts
Workaround for comments (Google Form or Padlet embedded in site)