'relationship' model created. Also, created index for 'composit key' so that all pairs are unique: so 'follower_id & followed_id' are unique in the db.
Created many<=to->one/one<-to=>many associations of Users models (followed vs follower), via :relationships model.
Created 2 pages: (1)following and (2) followers, including adding follower/following resources and actions, etc.  Added following/follower stats at a partial to pages.
Follow and Unfollow buttons working. Created RelationshipsController and we are using the 'create' and 'destroy' actions to create/destroy the 'relationship' between users.
Completed Sample Application!  Final step was creating db query, to pass into feed, to give feed ability to get the Microposts of Users you are 'following' and put that in a query together with your Microposts, to create the feed we wanted.