A detailed article about caching in Rails3:

Caching in Rails is covered occasionally. It is covered in very basic detail in the caching guide. Advanced caching is left to reader. Here’s where I come in.

Covers:

• Page Caching: not applicable to most real world apps
• Action Caching: a bit more useful than Page Caching, runs before_filters
• Fragment Caching: Store parts of views
• Rails.cache: Store anything at this level

Link: BroadcastingAdam – Advanced Caching in Rails via broadcastingadam.com