ZURB's Foundation is a front-end for quickly building applications and prototypes. It is similar to Twitter Bootstrap but uses Sass instead of LESS. Here you will learn the basics of the grid system, navigation, tooltips and more.
Caching at a low level is a great option when the view is too dynamic to cache and you need something flexible that can work anywhere in the application. Here I show a variety of ways to use Rails.cache with Active Record.